It isn't necessarily a bad thing, but it doesn't align with the idea of how good react is or the technical merits of it.

I also am not saying teams I have been on that picked react made the wrong choice. That's all in context and as you said startups are often in the "get things done" mentality where tech debt won't matter if you can't survive long enough for it to matter.

It’s good enough that the ecosystem outweighs the superiority of something like SolidJS.

React has React Native as part of its ecosystem. That’s a massive advantage. react-strict-dom is going to be a game changer for the development of universal apps.