Nobody is saying Godot should implement their own text engine. There are several available ones they can use, or just pick whatever the platform offers.
> Why would you want to render text in a gaming engine in the first place ...
Just about every game needs text, including Unicode text. Every proper engine handles it.
"Just about every game needs text, including Unicode text. Every proper engine handles it"
No, what they do is paste a few characters on screen, handling a more common subset of Unicode. They don't come close to handling most of the things I described above.
Not even Qt handles text well - Qt allows you to do some fun 3D things with text, but not you can't open 100K lines of formatted code like VSCode.
Webkit is just as bad - MS had to invent 'Monaco' a huge layer on top to be able to manage text properly and it's kind of a hack.
"All major platforms offer advanced text rendering support."
No, they don't realy.
I think you're missing a few pieces in your understanding of what the platform does in these contexts
The platform does not support text rendering for Qt and such platforms. They are rendered 'from scratch'.
Some platforms offer some built in components, but even they are quite limited.
No platform offers the ability, out of the box, to do for example, a 'coded editor' with properly highlighted syntax. Not even close.
"Most games do actual text rendering properly."
They are 'rendering text properly' for the extremely limited subset of text that they put on the screen.
Have you ever used even a basic 'text editor' in a game? No? Because they don't even do that.
" you can't open 100K lines of formatted code"
"You definitely can, but not naively."
'Natively' means nothing on the context of 'browser'. If you mean to say 'the browser doesn't do it out of the box' - then ok, yes, we agree. And why not, because it's extremely hard?
There are 0 comprehensive text APIs that are built upon gaming or even 3D engines today. Most of the barely handle basic text formatting. They put a few lines of text on the screen in a limited number of languages, and that's it.
There are very, very few platforms that offer comprehensive text rendering, including Qt, GTK, and native platform components - they're basic.
Providing comprehensive text API is not only something that has to be layered on top of those things - they also have to 'hack' those platforms to work around inherent bugs and limitations.
> Why would you want to render text in a gaming engine in the first place ...
Just about every game needs text, including Unicode text. Every proper engine handles it.