The basic thing I am saying is that if you call it a web browser and use the same core protocols etc., you have a practically infinite (for an individual) set of requirements to implement and will never be truly compatible.
What ideas like Tersenet and systems like Gemini propose is similar to what you say, except even simpler. HTML and ECMAScript are quite complex and have a lot of challenging expectations as far as performance and flexibility.
The idea is to try to break things off in a clean way that is feasible to implement without having to worry about a fuzzy and ever-expanding definition of what you have to support.
But what the parent is saying is you don't have to be compatible with 100% of websites. If you build a browser with good HTML/CSS/Javascript handling, you'll be compatible with the large majority of the web. Yes, there are other specs that are in use by a tiny portion of the web. But your browser can still exist if it doesn't support them. Users of that website will know or find out that they can't use your browser for that, but for every other user that browser could be exactly what they need.
> without having to worry about a fuzzy and ever-expanding definition of what you have to support.
It's only ever-expanding if you're trying to keep up with the Jones's. You can define a subset of the web you want to support and build a clean, small browser that supports that.
Will you? I very much doubt this is the case.
Because Google is following the old Microsoft playbook of "embrace/extend/extinguish". They throw shit at the WWW consortium partially to see what sticks, but also in the hopes that websites will adopt the shit, forcing other browsers to add the shit to be able to display those sites.
Google is incentivized to do this because, since nobody else can keep up with the shit-flinging, users switch to Chrome. Then Google gets everyone's data for free, further strengthening their monopoly.
That said, I fully support people trying to build new browsers.
I'll bite... why? Most websites follow HTML and ECMAScript. Why do you need to do anything Google does? Isn't the whole point of this project to decouple from what big tech companies do?
The vast majority of websites don't want to follow whatever Google-only shit they've come up with most recently, whether it's adtech, AMP, DRM, or whatever.