> I'm personally curious how far we could go with using just canvas and wasm
In a word: accessibility. HTML is inherently accessible - you can curl a webpage and read the contents of any (static) web page. If you curl an entirely <canvas> based web page, you'll walk away knowing only that the web page has a <canvas> element in it.
You mentioned Qt. I've never programmed a Qt app, but I went hunting for its accessibility features in the docs[1]. I'm encouraged that Qt takes accessibility and Assistive Technologies seriously. However, if you're coding a web page in canvas/wasm/Qt you're going to need to make sure all the content, links and additional accessibility/AT requirements get ported from the <canvas> into the surrounding DOM to make it accessible.
In a word: accessibility. HTML is inherently accessible - you can curl a webpage and read the contents of any (static) web page. If you curl an entirely <canvas> based web page, you'll walk away knowing only that the web page has a <canvas> element in it.
You mentioned Qt. I've never programmed a Qt app, but I went hunting for its accessibility features in the docs[1]. I'm encouraged that Qt takes accessibility and Assistive Technologies seriously. However, if you're coding a web page in canvas/wasm/Qt you're going to need to make sure all the content, links and additional accessibility/AT requirements get ported from the <canvas> into the surrounding DOM to make it accessible.
That's a huge amount of work!
[1] - https://doc.qt.io/qt-5/accessible.html