Orion is the first browser on iOS that has convinced me to move away from safari. From the Kagi team, and admittedly still in beta, it's fast, rejects telemetry, and allows install of Chrome and Firefox extensions. The built-in pop up and blocking is great, and nukes YT ads too.
Still a little rough around the edges (sometimes freezes; restart it; and switching orientation is slow), but the pros outweigh the cons.
It does allow installation of webextensions. Unfortunately, they are extremely buggy on iOS. I was pretty disappointed when uBlock Origin installed successfully but didn't do anything. Once the webextension support is stabilized, Orion can be a serious alternative to Safari.
Still a little rough around the edges (sometimes freezes; restart it; and switching orientation is slow), but the pros outweigh the cons.
https://browser.kagi.com/