I like the DOM. I think people keep forgetting all the small details, like being responsive (working on mobile and desktop) and many other issues related to privacy and usability. IMEs, dictionaries, spelling correction, etc... All of these happen in text areas. If you implement things yourself, say in canvas on a webpage, you can't provide these. For example if I misspel somethng the browser can lookup that word in the user's dictionary but your page can not as looking through a user's dictionary would be a privacy issue.
That said, if you want a non-DOM framework, surprisingly Google already provides it. It's called Flutter and it has the option to use a canvas, no DOM. You can see a large complex example at
Go there and type in NYC. You'll see text and images popup over the earth, etc. You'll see a toolbar and menus and a status bar etc... Click settings. The stuff that appears is all canvas. Click the Data Layers icon. The stuff that appears as all canvas. I think they finally made the search input box an input element for the reasons above but the rest is canvas.
Also note that canvas based input is also why Google Docs has so much trouble with emoji and non-English input.