Very opinionated narrow-sighted post with many doubtful conclusions. There are plenty of excellent whiteboarding tools out there, each has pros and cons. The price tag is not always a factor (especially in the corporate world). Figjam is neatly integrated with Figma, that's why it has excellent chances of survival at least for the UX and Product audience. We have just moved our team from Miro, which has way more powerful functionality and that was well-adopted into our workflows, to Figjam just because it's closer to design and everything is kept in one tool.

And there it definitely happens all the time when lots of people contribute to the same UI file. If it doesn't happen in your workflows, that doesn't mean it doesn't happen in the entire industry.