I partially agree with you, but additionally there's a whole set of employees who would be clearly redundant in any given company if that company decided to just use a simple, idiomatic, off the shelf UI system. Or even to implement one but without attempting to reinvent well understood patterns.

One reason so many single-person products are so nice is because that single developer didn't have the time and resources to try to re-think how buttons or drop downs or tabs should work. Instead, they just followed existing patterns.

Meanwhile when you have 3 designers and 5 engineers, with the natural ratio of figma sketch-to-production ready implementation being at least an order of magnitude, the only way to justify the design headcount is to make shit complicated.

But every company I worked at in the past 10 years or so eventually coalesced around a singular "design system" managed by one person or a small core team. But that just goes back to my original point - every company had their own design system, and there is not a single, industry-wide set of "rails".

The bigger issue I see with "got to keep lots of designers employed" problem is the series of pointless, trend-following redesigns you'd see all the time. That said, I've seen many design departments get absolutely slaughtered at a lot of web/SaaS companies in the past 3 years. A lot of the issue designers were working on in the web and mobile for the 25 years prior are now essentially "solved problems", and so, except for the integration of AI (where I've seen nearly every company just add a chat box and that AI star icon), it looks like there is a lot less to do.