My advice is to always go in short steps, proving the ground and getting to know the alternatives. I’d recommend installing f-droid and having fun testing all the free apps you can, removing google stuff one by one, then, after feeling comfortable, trying a custom rom, and when you eventually need a new phone, looking for a model more friendly to degoogling.
And not only an easy thing to do, but something that bothers the big tech a lot! If it didn’t bother, they wouldn’t care to invest so much in making it harder for us, and if it bothers them, it means we’re on the right track.
Linux market share is increasing even in the charts with all OSes, desktop and mobile.
So, if we consider a classroom, it’s roughly 1 or 2 students using linux in each class. I don’t think it’s too far off from real life experience.
They count based on useragent info from accesses to websites using statcounter analytics.
On the other hand, if you just want to make people uneasy and some even angry, you can just use and share bitmaps.