It'll probably end up showing how difficult and resource-consuming it is to build a browser from scratch. However, the solution for that problem isn't on the implementation side at all. It's the uncontrolled (and possibly intentional) scope creep of the web standards that led to this unflattering situation. The solution must address that.

I remember an X post from week or two back on how apparently some kind of a "hack" was required to make LB work with google docs. The last 10% (which takes 90% of the time) is probably going to be full of those instead of just implementing the spec as one might naively assume. LB can't sadly just ignore those requirements either. Not without significant grassroots movement around it as support. And the punchline is that the scope creep is ongoing so LB is playing major game of catch up.

In a talk they said they send bug reports for the specs.