Because the Zubrs they have will be far from enough to spearhead an amphibious assault and we do not know how many they actually plan to order and how long it will take to fulfill their o
If they get some 20 Zubrs or so, then maybe we can start talking about Zubrs replacing 071s as the primary means of spearheading the first wave of an amphibious assault.
Until then, I think LPDs are the best (or at least the "least worst") option for the PLA to conduct a first wave amphibious assault with.
Spearhead and main force are not the same thing.
And as I said, the spearhead will be special forces, airborne (paratroopers) and helicopter borne air cav.
Trying to find well hidden AShM and SAM launchers from the skies can be hard, that’s why you need boots on the ground to help.
Those spearhead forces are primarily there to locate and destroy enemy high value targets with either direct action and/or directing air and missile strikes in.
Their secondary job is to draw enemy forces out of hiding for the Air Force and missile corps to easier pound.
For the beach landings themselves, you will see the Zubrs, and maybe 726s moving in first to put boots and treads on the ground, but even at extended ranges, the 071s will still be well within coastal AShM range using 726s.
All LCACs and 726s does is allow the LPDs to stay out of coastal artillery range at best, but the 071s can launch their 726s directly from port on Chinese coast and they will still be within AShM range of Taiwan’s coastal batteries. So there is little benefit from sitting further back from the coast, as that just gives the defenders more time and opportunity to shoot at you since you will be on station far longer.
Yes, reducing the distance to the coast increases risk, but so does staying on station for a long time, as you would have to if you were relying on 726s to land the bulk of the forces carried by those 071s at extended ranges.
To do that, you need to maintain intensive naval and air SEAD/DEAD, CAP, interdiction, CAS and strike operations for several hours at least.
In my estimation, the increase in risk to the 071 from forward deploying to a few miles off the coast for maybe half an hour at most before pulling back; is going to be lower than for those 071s to stay a few dozen miles off the coast for most of the day.
It’s far easier to mount a massive naval and air operation to close down the airspace over the beachhead and deploy swarms of drones, CAS birds and strikers to almost instantly hit any enemy forces that reveal themselves for an hour or two at most; rather than having to do pretty much the same thing for several hours more.
Not only is the prolonged cordon time demand significantly more attacking assets to be made available to allow for rotations on and off station for refuelling and re-arming; you may also have to settle for a far less robust presence and attack on account of needing to hold assets back as reserves to be used when your first wave of assets run low on fuel and/or ammo; it also gives the enemy much time to organise a big counter attack to try and punch through your cordon to hit those high value LPDs and warship escorts.
Your suggested approach is the western steamroller method to minimise losses. But that takes a long time of preparatory strikes to degrade enemy defences sufficiently to allow that approach.
If you follow the western playbook, you only deploy LDPs once all the AShM and air threat has been completely elmiminted and you only got coastal artillery to worry about.
In that position, so long as your LPDs stay a few score miles off the coast, they are perfectly safe. So it doesn’t matter if it takes all day for their LCACs to ferry all the troops and gear ashore. The PLAN won’t have that luxury of being able to count on having the leisurely time to create that kind of a safe zone.
If you cannot stay out of enemy attack range, as the PLAN won’t be able to until they can kill every enemy AShM launched and fighter (which they are unlikely to be given enough time to do), then the best way to minimise risk is to minimise your exposure time to those threats.
There is nothing stopping the PLAN 071s from launching their 726s at extended ranges to accompany their Zubrs on the way in.
Only the PLAN 071s won’t be sitting around waiting for their 726s to come back for a second load. They will be racing toward shore at full speed themselves, while all the IFVs start coming out of the vehicle deck to pack the well deck.
Once the 071s get close enough to shore, the IFVs are going to pile out ASAP, then the 071s and escorts are free to race back as fast as they charged in.