Firefox and uBlock Origin. Hard requirement for all platforms but iOS, which doesn't allow alternative browsers. Still, ad blocking has come a long way since I started using iOS, and we have uBlock Lite now, which I think is what Chrome users get on computers? It's system wide and it works well. I have a few other ad blockers I can cycle between (you shouldn't combine them), including Wipr2 and AdGuard. Wipr2 is one of the best Apple-ecosystem ad blockers, but I'm using uBlock because I like the brand and so far it's been fine. Used AdGuard before. If uBlock fails me on iOS, I won't fault it (the blame would lie with iOS) and I'll happily go back to Wipr2. And I use Safari on iOS, though I also have Firefox installed, synced to my work Firefox profile, for reasons.

I have Safari on my Macs (I don't think it can be removed?) and it's kinda dogshit, but I use it from time to time. A couple things work better with Safari. Like if you want to do online ordering, being able to use Apple Pay on the MacBook is awesome. I don't think Firefox can use the fingerprint reader.