I would say that we shouldn't have an advanced web application unless we need an advanced web application. Most of the time, we really don't need it.

This presumes that heavy toolchains are a prerequisite of advanced web applications. The toolchains seem to be more about ergonomics than creating new capabilities.

A large part of the toolchains are also bandaids on a lot of unnecessary friction caused by changing standards and moving targets. The web platform is almost to the point where a lot of those bandaids could just be ripped off: ES2015 modules are directly supported in most browsers today, same with CSS modules / syntax through ES2017 or more recent / and so forth, and protocol upgrades in HTTP2 and HTTP3 remove a lot of the performance-specific needs for things like bundling and minification.

The biggest hurdle to ripping off the bandaids (as with so many things in software development) is the rough edges of the long tail of legacy code. The biggest example being that there's still so much code written for CommonJS (or AMD) that needs shims to play well in ES2015 module worlds. (Because no one wants to stop the Node world and rewrite everything all at once.)

pika.dev is coming really close to shimming a ton of existing libraries into module world.

I'm not at all convinced that the heavyweight toolchains have led to any improvement in webapp quality. Maybe there are rockstar apps out there I just haven't seen, but for the most part the web these days is vastly more bloated and somewhat less stable than it used to be, without doing anything more that any user actually wants. This is not progress.

I can't think of a case in the past decade where I've really wanted to have a web application rather than a proper native thick client.

I understand the attraction, and I've had to build my fair share of them, but I don't like it at all.

Actually yes, we don't need SPAs to display basic blocks of text with some animation.