If you share wifi with someone who has done the search on their devices, It will do that.

I’ve never noticed any ads so it does it job for me. As for Collabora Office, It is to my knowledge - https://github.com/CollaboraOnline/online (It’s also used for the iOS/Android apps).

On iPhone/iOS you can download content blockers to have adblocking on it(Limited to Safari only); Personally I use Adguard Pro.

I think I’ve seen some people use a VPN/DNS to have systemwide blocking but I’ve not looked into that personally as my router supports it.

I use Collabora Office as my Office Suite, again on iOS; LibreOffice on my computers.

If they can make money off you, they will.

If they wanted to read on a phone/Normal display, they wouldn’t have asked for recommendations.

Personally I just run a ThinkCentre mini pc with Fedora. Bluetooth keyboard/trackpad; Sorted. Not as convenient as a remote but don’t need to fiddle with stuff.

You can get them cheap used on eBay