[Shadonototra]

multiple reasons

- it's hard to make declarative UIs with C# (recent versions try to make it easier, but it's still not there)

- making UIs is hard, making game UIs is even more hard because there is no rule to make a UI, it depends on many factors (art style, game genre, platform you target, input you support)

- making something customizable, serializable and performant is very hard

you are better making your own that suits your need, hence people rely on 3rd party solutions that exactly solve their use case

[redefine_net]

I don't get why they don't make HTML-compatible frames you could just rotate in 3D. in my mind - if you said UI you said HTML. (and JS and CSS)

[Shadonototra]

because web tech sucks, it performs poorly, it's even more true when you start to target ressource constrained devices (mobile and consoles)

8ms is your framebudget for 120 FPS