A type 076 LHA with light aircarft carrier capability vs an aircraft carrier is like a jack of all trades vs a specialist. A jack of all trades can be more versatile but a specialist can do things much better.
It is a matter of distribution and employment of assets and resources. If you have limited resources you need a type 076 to do both amphibious assault jobs and light aircraft carrier jobs. If you are rich, just add more aircraft carrier.
Why would US Marines, an independent military branch, chose to use LHA to base their F-35B is may be because their missions rest mainly on amphibious assaults, and having an independent air wing (from USN aircraft carriers and USN aircrafts) means they would not need to tie their mission destinations to movements and deployments of USN aircraft carriers. Of course, both USN and US Marines can always work together but sometimes US Marines may have to work alone.
Unlike US Marines, PLA Marines are part of PLA Navy, they work as a part of PLAN deployment. Do they need a separate air wing to base on an LHA or LHD?
I think the point is do you want to use manned aircraft like F-35 to support your amphibious assauts, or do you prefer to use armed strike drones? And what will the design of type 076 be? Will it be designed for strike drones or manned fixed wing strike jets?
We shall have the anwer when type 076 appear.