For your mobile needs, uBlock Origin also works great in Firefox for Android!
This is, honestly, one of the things that brought me back to Android. Content blockers on mobile Safari just didn't work as well for me.
Yeah. There's a glimmer of hope that Apple being forced to open the app store will allow us to use Firefox on iOS, too. Fingers crossed!
There are several ad blockers or content blockers (free and paid) on iOS with varying experiences (and sometimes annoyances due to the platform limit on the number of rules a blocker can include). Firefox Focus on iOS comes a built-in blocker. Additionally, using something like NextDNS – which allows adding the same filter lists as uBlock Origin – also helps. Of course, these will not allow easy element picking and blocking.
I use Brave on iOS. I know it's forced to be just a webkit skin there, but it's better, at least.