Very few switch games use Vulkan on the Switch. NVN is the true native graphics API on the Switch, which is Nvidia's API. Those that have tried Vulkan on Switch usually end up ditching it for NVN as Vulkan leaves too much performance on the table on a system with little power to spare.

Sure, I'm not saying Sony is any better in this regard. They copy worst ideas from each other.

Right, but my point is that this isn’t some famous malicious intentional lock-in by “evil Microsoft” — it’s how every console is designed. (And arguably Xbox has an advantage here because it shares DirectX with Windows)

There’s no evil MS lock-in here.

Not really. It has nothing to do with console idea or form factor, it's just how these messed up companies are "designed" in using anti-competitive methods. See Steam Deck which uses Vulkan just fine.

There is absolutely lock-in in MS and Sony's approaches. There is no inherent need in it just becasue it's a console.