That's part of it sure, but it also doesn't really provide any benefit that makes the hassle of learning all that worthwhile to your average person. They get everything set up and learn how to fix things when they open in the wrong containers, but what does all that get them in the end? Tech companies wont have as clear a picture of what you do while using Firefox. They'll still spy on you through your phone, and their apps, and their little home assistants, and your searches, and your purchases, and your posts... all you've done is made it slightly more difficult to correlate that data with your browser activity.