It’s not that we don’t want to dream. I’m right there with you. The issue with your examples is that they aren’t political but UI design languages are. Imagine if the UN appointed one ambassador to unilaterally represent every Slavic country simply because they all happen to speak similar languages or be located close to one another.

The issue lies not with the implementation but the requirements themselves. Each platform has its own design philosophies that either conflict with other platforms or, in some cases, are simply so vague as to be incoherent. Sometimes it even looks like competitive subterfuge.

I think tailoring each app to the platform you're targeting will always look better than cutting corners. Especially if you can integrate your app into the native styles of the target platform rather than just embedding custom CSS into every application so the target platforms lose all character entirely

It depends on who you ask whether software development is like agriculture or like some other types of work. Building a cathedral still takes about a 100 years like it did half a millenium ago.