On the earlier point made about Taiwan countering J20s with anti stealth radars and upgraded F16s. Well that simply won't work for 2 reasons.
1) Taiwan doesn't have any anti stealth radars
2) Taiwan has zero strategic depth.
Anti-stealth radars work for China because geography and strategic depth means China will start any conflict with those radars way out of range of most enemy weapons (and things like cruise missiles could be easily defended against if the enemy was foolish enough to try and hit high value targets with those only, but a more co-ordinated attack would put enemy manned assets in harms way).
The enemy will have to physically close with the Chinese mainland in order to try and engage those radars with any chance of success, allowing Chinese air defences the time and distance needed to detect stealth targets and vector friendlies to intercept.
Even if you put anti-stealth radars on Taiwan, as soon as they light up, the PLA will be able to detect them and attack them with land based weapons without having to send any stealth fighters anywhere near them.
Even if Taiwan somehow manages to keep one or two radars safe, it cannot shoot and scoot with its airports. Being able to detect J20s while having all your fancy new F16Vs destroyed or grounded won't do you much good either.
Any realistic Taiwan scenario will see J20s hand back taking pot shots with BVRAAMs while Chinese cruise and ballistic missiles lays waste to all airfields and long stretches of highway on Taiwan.
Any ROCAF F16s that get airborne will have the unenviable choice of flying into the teeth of Chinese air defences to try and engage 5th gen stealth fighters; or hang back over friendly SAM umbrellas while their home bases and all alternative runways are destroyed.
The PLAAF can literally just fly circles over the Chinese coast for a few hours and wait for the ROCAF fighters to either come to them, in which case they will face not only a technologically and numerically superior PLAAF, but also be fully engaged by both land and naval based Chinese air defences; or for the ROCAF fighters to run out of fuel with nowhere to land and crash without the PLAAF pilots having to fire a single shot.
After the air threat is neutralised, the PLA will just send swarms of their new armed drones across.
Now people might see what China's radar drones are all about - there is no need to go actively hunting for SAMs when the PLA can put a persistent 24/7 real time anti radiation drone net over all of Taiwan, with manned fast jets acting as QRF.
You can have maybe 1-2 radar drone passively scanning for any radar emissions with 5-10 nearby regular drones datalinked to it(them), ready to instantly strike any radiating targets the radar drone flags up.
Any time a radar lights up, it is risking near immediate attack from a patrolling drone.
Even if a SAM battery shoots down the drones, it just pinpointed its position for PLAAF Wild weasels to come pay them a visit, potentially within minutes of them lighting up.
Any attempt to hold a beach during a PLA rolling artillery barrage; with a hundred armed PLA drones overhead providing live targeting data for every metre of the target beach; and/or directly engaging high value targets of opportunity with their own weapons... Well, shooting fish in a barrel really springs to mind.
If it really came to it, China will be able to overwhelm Taiwan's defences far quicker, and with far fewer losses than most western pundits would dream possible.
But that is drifting off topic again.
