"Nobody" here means few, or more loosely, much fewer teams than before, not "literally 0 people/teams".

And the group mentioned is (I deduce) not generally individual devs, enterprise devs building some internal thing, and so on but teams in companies doing public-facing SaaS, teams in startups, companies like Amazon/Google/Facebook/Apple all the way to AirBnB etc, and so on.

So, you don't really need stats for that.

Yes, exactly. The larger the team, the more likely someone is a front end expert and wants to use latest cool framework, which will by its nature require a build step. Even for something simpler, you'll probably want it for cache busting, minimization, etc.