You wouldn’t concern yourself with the legality, if your threat vector includes the traceability of the phone number.

And regarding your (in this context) nonsensical privilege remark: I live in such a country. Yet I have used such numbers.

If somebody is that paranoid (or in a situation where that level of secrecy is necessary) they would not use a number that is traceable to them… So it doesn’t matter if they have your phone number or not.

he’s using google chrome

That answers how it happens. My guess is that he googled things relating to submarines or his browsing behavior regarding that game caused him to be grouped as potentially interested in submarines. If you are using chrome everything you do will be collected and used for marketing. No amount of extensions will save that since the browser itself is spying. If you want to minimize this happening you have to switch browser (brave is the closest to chrome) and stop using google for search.

Someone has a recommendation about how to handle these services?

You don’t. Apple is notorious for their walled garden approach. Microsoft has no interest in supporting Linux (why should they?). Don’t know about Google.

I am pretty happy with pcloud. They offer lifetime licenses that are really worth it if you intend to stick with them long term. The automatic Backup works great and AFAIK they have clients for all major platform’s. The android client could be better, but Windows and Linux works great. Don’t miss any functionality and the connection (at least here in Germany) is fast.

That is not the point… The anger stems from Americans deciding they want something and then strong arming other countries into complying.

That is just so much not the point… The anger stems from americans deciding they want something and EU kissing their asses to cater to all their needs. Just the fact that this

You seem to have three desktop portals installed. Gnome, KDE and lxqt. Only use one.