Comment by xp84
> document viewer, remote paperwork machine, and cross-platform application framework
Can I get a show of hands for anyone else who has had multiple jobs where The Frontend People have decided that in order to show something that can only honestly be defined as "a basic document" or complete a few simple <form> tags, the tooling necessary for the job is a React or Next.js app over 1,000 NPM dependencies, and fully reimplementing all built-in functionality from scratch in JS? The Web is simply the land of excess. Nothing is too simple to be overengineered poorly in JavaScript.
This would simply not be possible, if basic web browsers were more popular. The React / Next.js app wouldn't run, and then the users would complain, and the Frontend People would try to say "just use the WHATWG VM", and then the Enterprise People would say "we've blocked that so people can't play video games at work: fix your end" (ignoring that they only blocked programs named chrome.exe, and everyone's got Firefox or a renamed Chrome installed), and then the Frontend People would have to fix it because that's what the client demands. (For B2B, at least, but B2B is lucrative enough that best-practices proliferate.)
It's a chicken-and-egg problem. The harmful consequences of Postel's principle are well-known, but the solutions are also well-known. We only need to get past a certain threshold before the problem's effectively solved, and that can be done by starting in a particular domain and working our way outwards.