Fairly obvious? On the Tibetan plateau and on the Indian border, a fairly lighter and more agile helicopter would suit the terrain better, while on the Taiwan straight one could justify the use of heavier platforms but with the arrival of the Type 076 class of amphibious carrier ship, drones seem to be 'replacement' to helicopters in providing fire support in an amphibious operation. Of course helicopters have not been replaced but their roles have been diminished with the advent of larger more capable attack drones.
Absolutely, fairly obvious.
You seem to not understand that a "heavier helicopter" means that a given helicopter can perform and fly in a way which is at least equal to a lighter helicopter, while retaining greater range, armour, payload, or a combination of those.
Which is to say, if you are wanting to talk about a desirable helicopter for high altitude regions -- a heavier attack helicopter is better than a lighter attack helicopter because the heavier attack helicopter can carry the same payload while retaining far superior hot and high performance.
As for a Taiwan scenario -- I'm not sure why you think 076 or attack drones fit into this. Attack helicopters are not obsolete because drones and UCAVs exist. Attack helicopters will absolutely remain relevant for years and decades to come.
Overall, there should be a recognition that Z-21 will be superior to Z-10 in may ways, and also recognition that attack helicopters will remain relevant going forwards, thus accepting that the PLA has a need for a new attack helicopter to begin with.
With the appearance of the Z-21, as it being mostly based off of the Z-20 platform, it's clear the PLA wanted to develop a heavy attack helicopter quickly over something like a tilt-rotor/pusher prop design. What I question is why the rush? Where is the crucial need for a heavy attack platform where speed of induction is prioritized over creating a newer and more advanced helicopter program for the future?
With some speculation on my end here, Z-21 either could be a stopgap measure where operating a heavy attack helicopter right now is important, as to train pilots for when the PLA tries to develop a next generation heavier attack helicopter. Or.. wild theory, the PLA is unsure about the future of drone warfare, helicopters, and amphibious operations. Thus betting on a safer option over a riskier program that might end up falling flat.
Yes, now you are catching on.
To me, the role for Z-21 seems fairly obvious. The existence of Z-21 says to me, the PLA wanted:
- a new heavy attack helicopter with significantly greater payload, armour, and/or fuel than Z-10, or the ability to carry the same payload as Z-10 while being able to fly in more challenging or higher altitude environments, while also retaining more growth capacity than Z-10
- be sufficiently low risk that it can have a relatively short developmental period, to enter service with minimal delay between time from project initiation to IOC, as opposed to other more challenging drivetrains such as coaxial+pushprop or tilt rotor or other configurations
- pursue a platform with commonality with the Z-20, their current mainstay medium weight utility helicopter, which offers benefits for logistics
That all seems highly obvious and reasonable to me, so I don't see why there should be any skepticism towards these ideas.