I use Orion on iOS which actually does support both firefox and chrome extensions (though very much a work in progress compared to the mac OS version). Ublock origin doesn’t work unfortunately but the built in content blocker is pretty much just as good. Orion is noticeably snappier to load pages than Safari (I guess because it doesn’t have Apple’s telemetry?), blocks all youtube ads, and can use Kagi as the default search engine. Just because every browser on iOS has to use the same rendering engine doesn’t mean they don’t come with their own features or perform the same in terms of speed.
OTOH with Safari you do get better extension support through the app store, can use iCloud private relay, and is theoretically better in terms of fingerprinting.
89% on Safari with Adguard extension.
100% on Orion with uBlock origin installed (funny enough, even without uBlock I get 100% using Orion’s built in content blocking)
100% on Brave
70% on Librewolf
39% on DDG browser
All tests done on macOS ventura.