If we use my original timeline of 6 years from now, then USAF would have around 550 to 600 F-35As in service by then (about 300 now, 43 to 48 delivery by per year for the foreseeable future). Deploying even a quarter of that to Pacific theater would be hard to do since America has so much other commitment. The availability of F-22 is a lot lower (far and away the lowest in USAF and only about 110 is even in active/non national guard squadrons IIRC). Getting 1 squadron of F-22 is probably the most they can do. And as I described earlier, it would not be practical to expect more than 120 F-35B/Cs in theater. PLAAF would have a huge numbers advantage between J-20/J-35 in any conflict. On top of that, there should be a small number of H-20 and JH-20 available for combat by then.
Air strips are not created equally. Military ones are defended and have personnel available to repair runways. Air strips along Ryuku islands are not. More importantly, military air bases have people trained to maintain the aircraft and have shelters that at least offer some protection from missile strikes. You are not going to get that with non-military bases where even PGMs can probably put it out of use. USAF will also not risk its F-35As get destroyed on the ground.
If we compare this to Japan, most of the journey from mainland to Japanese waters will not have to face air defense radars or SAMs. One must ask how many air bases in Japan is even capable of hosting USAF F-35s and keeping them protected from LACMs. That would require hardened aircraft shelter and ground staff who are capable of maintaining F-35s. I would imagine that's a small number that H-20/JH-20 would have an easier time of taking out. Just as importantly, the flight route from Japan to Taiwan would be over international waters without air defense radar/missiles for protection. The tankers would be really facing the danger of PLAAF interception. It remains to be seen how well USAF/USN tankers can survive the J-20 threat in real combat. Needless to say, I think F-35A coming to the rescue of Taiwan to really be limited. So, the vast majority of effective F-35 protection hours would rest in the 100+ F-35B/Cs in the area. PLAAF would not have to strike down significant number of F-35s in such a scenario. They just need to not lose too many of their own advanced aircraft. They will likely also send a lot of J-6 drones and UAVs into the air space also. It won't just be fighter jet vs fighter jet. At a certain point, the air wing and their crew member would get worn out by repeated sorties.
Stating as a fact that US would have some more important commitments than putting as many planes into the fight as possible, against China seems very unrealistic to me. Sure, not ALL planes could possibly be sent to the war - but it's perfectly plausible the US would try to send as many as it can. What other commitments are there? To protect the mainland US? Sure, a few planes might be needed for that, to try to guard against sporadic, low volume bomber/ cruise missile incursions. But older planes can do that, F-35s aren't needed for that.
Other places around the world? Unless there's a war that US is involved in - I don't see the US choosing to commit many planes elsewhere. As we're seeing in Ukraine now, the US chose not to get itself involved, openly stating it'd not send any forces. Pull-out from Afghanistan can also be looked at in a similar light. The US trying to focus itself completely on China and being ready to send a maximum level force against China on a fairly short notice.
So, short of another large war - something on the scale of Russia going to war with NATO member countries in Europe - it seems perfectly plausible the US would have all the stealth fighters (and a better part of their fighter force overall as well) available against China.
Available here meaning available to be sent into theater when basing capacity and maintenance limits allow it.
I am not necessarily saying they'd be sending 500 or 1000 or any other specific figure - but to say unequivocally that the US could not send more than 300 F35/F22 seems like a blind faith dogmatic thing to say. Such underestimations of adversary were known to lead to defeats in wars, in historic terms.
F-35B would most likely be mostly used from ground bases, not from ships. In a sense, that's their primary role - to be used from fairly short runways, from austere and makeshift air bases.
Yes, not all bases are equal and some airports would support fewer sorties, of course. But a makeshift base doing 24 sorties per day is still better than no base. Even if some other base, with greater number of personnel, can manage 100 sorties. And yes, while a well manned and equipped base could repair a runways after an attack in a matter of hours, (Iraq did that in 1991) a less well equipped and manned base might need a day or two. But it'd still help quite a bit.
Expecting that the US would be limited to just these few bases that it operates today would be gross underestimation of the adversary which is just not logical for US to do. It'd amount to US choosing to fight with one hand tied behind their back, on their own.
F-35 is a weapon like any other. To not use because of fear of losing it makes little sense. So saying that F-35 would definitely not risk it getting destroyed on the ground makes no sense. There's just as equal possibility that the US will very much use it from bases 1000 or 1500 km away, bases without hardened shelters and so on.
Having satellites and BM/CMs doesn't equal precise hits on planes on the ground. There's gonna be a lot of cat and mouse game, a lot of hiding and reshuffling, and a lot of misses if any side (US or china) tries to actually go for individual planes parked on the ground using very long range stand off attacks.
The route US/JP planes would use would be over or the east of Ryukyu islands. So there'd indeed be some air defense protection. Both from ground SAMs and pretty numerous naval assets, east of those islands.
None of my writeups are saying "China can't do this or that", they're here to try to present something I believe is a more objective possibility - where both sides would face considerable issues. To expect that the US would just sit tight and make a token effort doesn't seem realistic - when it'd be choosing not to use so many options available to it. If US really concluded it can't send more than a few hundred planes at once against china - then the US would not choose to participate in the war at all. It just wouldn't make sense.
Japan getting involved in such a war is a given, really.
And with many bases being literally shared by US and JPN forces, with incursions of Chinese assets into JPN territory and JPN SAMs shooting at Chinese planes, and JPNs SAM assets being attacked by China - it's basically inevitable that Japan would very quickly go all in against China, since the US be there, also all-in, as well.
If for any reason Japan DOESN'T want to get involved - the US would choose not to participate in the war either. Japan is simply that crucial.
