I just rebuilt a custom Select/Combobox component in react for a Business, and I promise you I had no intention of differentiating. I wish I could have used more native browser behaviour.

Too reductive.

Businesses differentiate to create revenue. Standardization and commoditization are important strategies as well. “Commoditize your complementary goods” and all that.

A web design shop may want to visually differentiate and therefore not use openui. But a restaurant that just wants to have a simple website probably doesn’t want either 1) a crappy looking website, or 2) to invest heavily in web design

Allowing for nuanced CSS selectors on each part of these components would get you 90% of the way toward resolving that tension.

Businesses differentiate when there's a good reason or no common solution. Nobody creates a new calendar picker or database or... "just because" but because there's no easy alternative. Yeah, there will be exceptions, but if you're paid to create something, your manager will usually not be impressed by "but the wheel I reinvented is slightly different!", unless you justify it with a specific requirement.

There’s no tension, you’re just wording this to make it sound like there’s one.

The things that standards consolidate and the things on which business differentiate are entirely different things.

Most business just adopt something existing, we saw this with Bootstrap, then with Material UI. Now things are a bit more diverse but still.

I feel like the pressure to differentiate is coming from internal design departments rather than business itself in 90% of cases. It's just people generating extra work for other people.

No one prevents businesses from using their custom implementations if they so wish. Just as nothing prevents them from doing so on literally every platform from desktop OSes to mobile OSes

Differentiation on UI components adds no value. This is the place for standardization. Users want them familiar.