PCB fabrication exists because hierarchical systems can't assemble electronics without PCBs.
Making a PCB in a small chaotic team (or even alone, damn, who in hw didn't etch their own PCBs as a kid?) is totally possible and quite easy; now making them to tight specs to make them compatible with a vertical manufacturing giant is incredibly hard (yet doable).
I was running an anarchic hardware design and manufacturing shop until last year (now I just have a bunch of unused equipment at home; can't come up with ideas on what to do). The problem wasn't in production, the problem was in sales - monopolist shops took over whole distribution networks and won't let an outsider in without getting their cut.
What would you need electronics devices for, anyway? Other than run Android that's designed to be ridiculously complex and uniform, alienating system with a sprawl of flaws and horrible centralization; catering hardware for smartphone industry is exactly hard because of hierarchical system in existence. Sure, there is an ecosystem of apps... that get rewritten on a monthly basis, cloned and vibecoded in minutes. And operating system vulnerabilities get scaled worldwide in an instant as everyone has exact same system.
I'd say, we'd have way more beauty in the world and way more security if our hardware was not unified. And for that we'd need to get rid of hierarchical optimizations. Which is not going to happen... on a global scale, that is, I'm soldering my nonsence equipment in a non-standard way now and do not care.
Here is a customary link to my friend working without a PCB at all https://www.youtube.com/watch?v=xo8qckXgNNw I just love rewatching this sick video.