I never got as far as making different profiles, but I do a few things:
On mobile I use Mull and Privacy Browser. I don’t know which I prefer. Mull has ublock origin, PB has built-in filters. They get the job done. I used universal-android-debloater to get rid of the Google bits and I use some other apps that are known to not have trackers. On top of that I have tried out different things like Blokada and InviZible Pro.
On my computer I use qutebrowser mostly, and sometimes Librewolf. qutebrowser is not really a secure browser, but they don’t pretend to be. I have some ad filters and host filters set up with qutebrowser.
Filters
c.content.blocking.adblock.lists = [
"https://easylist.to/easylist/easylist.txt",
"https://easylist.to/easylist/easyprivacy.txt",
"https://secure.fanboy.co.nz/fanboy-cookiemonster.txt",
"https://easylist.to/easylist/fanboy-social.txt",
"https://secure.fanboy.co.nz/fanboy-annoyance.txt",
"https://easylist-downloads.adblockplus.org/liste_fr.txt"
]
c.content.blocking.hosts.lists = [
"https://energized.pro/unified/formats/hosts.txt",
"https://raw.githubusercontent.com/d3ward/toolz/master/src/d3host.txt",
"http://sbc.io/hosts/alternates/fakenews-gambling-porn/hosts",
"https://pgl.yoyo.org/as/serverlist.php?showintro=0;hostformat=hosts",
"https://someonewhocares.org/hosts/hosts"]
On Librewolf I use some extensions, like LibRedirect and LocalCDN and uBO.
I don’t use Dropbox or Google Drive. To keep things synced I just use Syncthing.
On all devices, I use a password manager, 2FA, etc.
RE: gemini — I used to have a gemini capsule. I still take a look around from time to time. I use amfora though. Lagrange is great, I have it on my mobile.