My thought is that it is a dead-end. You don't need to extend HTML with data binding. You need functions, and you need an appropriate language to write functions, it can be PHP, JS, but not weird HTML attributes.
Yeah, after revisiting it again and also checking out your article I find my comments a bit too harsh and functional-approach-biased. But I'm in general no fan of Svelte or Vue approaches – for me as a lifelong React junkie this is all extra complexity i hate. Maybe my brain is now rooted and wired in the React so deeply it cannot accept anything else, but when I try to do something with Vue, it is just screaming: Too hard! Too many redundant entities spawned around! I just need my function, my reducer and my side-effects and I can do everything with these three! Like, I want to do this: https://codesandbox.io/p/sandbox/strange-hofstadter-kd59k6 It is a beautiful functional example of React's power. How do I even do it in OOHtml or Vue or Svelte? I still can not learn.
I love how we can talk about differences and preferences here like this. Now, I can't wait to put my thoughts further together on the pros and cons of a HTML-first approach like OOHTML's vs a JS-first approach like React's and why there seem to be strong opinions either way. I'm happy to share a link under here when I do put that together.