You're conveniently missing the point that there is an actually labeled telemarketing partner that is opt-out. That's not user habit collection. You're also missing that "random future studies" should not be auto-enabled by default either. Finally, the topic of this particular post is about categorizing search queries, which as far as they describe it isn't something your browser should care about.

The only thing that may be legitimate is, as you say, actual UX and feature usage. But for that to be done properly, you have to ask and make it opt-in, as with any data collection scheme. It's actually a requirement in some places.

The point is, people give shit to chrome because "evil google collects your habits data and monetize them", while people like you are a-ok with Firefox openly sending data to a third-party marketing partner on opt-out conditions and, as demonstrated by today's post, adding more collection that have absolutely nothing to do with the behavior of the browser and all to do with user habits.