Depending on web technology does not seem to be a problem for now. Nyxt, at the moment, is targeted as a browser after all. However, the “contemporary” web has lived much shorter than Lisp and I think it’s better to at least maintain the possibility of developing a pure Lisp variant. Maybe someday “contemporary” web will die, maybe Lisp takes over again, who knows.
I think the main obstacle would be replacing the parenscript part with pure Lisp. Nyxt abstract over web engine using RPC and make it easy to switch between web engine, which is good. Trying to maintain a Lisp interface (which has a parenscript backend) instead of calling parenscript directly from arbitrary places would make hypothetically switch to non-JS technology easy. Do people think this principle is desirable? Is it already being followed in current practice? I haven’t read through all the codebase, so am not sure about the second question.