Other companies have made the same mistake as Amiga, before and after.
They spent a ton of R&D getting ahead on things that would be commoditized in a few years. Later, their sound card had to be better than the best of a half-dozen PC variants, and so did the video card, CPU, monitor, keyboard, disk drive, etc, etc.
Sure, they could have bought commodity versions of some of those (and probably did), but then they’d have to be the best at choosing commodity components, and there were 100’s of strong competitors doing just that for PCs.
Now that moore’s law is slowing down, and everything has long-moved into system on chips, vertical integration seems to make sense again (look at Apple).
Android was trying to create an ecosystem of interchangeable hardware vendors (like Microsoft did with DOS, and, later, Windows), but it basically failed because driver compatibility is so poor in that space, and key components, like cell modems are locked behind anticompetitive OEM licensing agreements.
Android succeeded at other things, but it’s definitely not the case that you can assemble components into something with better specs than a flagship android for half the price, even if you had access to a pick + place / IC soldering machine. It was/is that way for desktop PCs.