I am currently building an app for internal use, and because I’m obsessive about presentation, I ironed out every wrinkle in this department. It’s 100% fluid, there are no layout shifts, no surprises anywhere. You would never know it’s not native. But I will admit it took a lot of effort to hunt down all the little idiosyncrasies and fix them.
I think a problem with frontend web development is that there are a lot of mediocre practices that became standard operating procedure. When I do this type of work, I try to keep the dependencies very lean and write a lot of stuff from scratch.
it is just totally possible, there are so many web api-s, you just need to be a good programmer and study a lot
you will not really find or use big web apps because
1. most companies have already built their native apps with mobile engineers
2. web "programmers" or rather designers are stuck with old tech
3. web apps will start to become strategic targets(!) by most developers/companies if you are sure they are cross platform (which was crippled by Apple and now they even try to eliminate modern web capabilities on iOS