How is this related?
It doesn't matter which engine is used in general, the only problem here is Sony.
It isn't technical.
Fortnite proved it when it 'mistakenly' allowed PS4 players to play with Xbox One players due to a 'configuration issue'.
Exactly. No Vulkan support is the same problem as not allowing cross play - lock-in in case of MS and Sony. At least Nintendo support Vulkan on Switch:
I suppose they might use NVM to interface with Nintendo specific hardware, they don't need it for graphics. So if engine developers are smart, they minimize NVM usage to only those corner cases, since there is no need to reinvent the wheel and duplicate work.
>yet is used as much as GL ES 1.0 was on the PS3.
Any Vulkan based engine can use it. Wasn't there Doom release for Switch?