NextDNS [0] has proven very useful for me on iOS. Firefox is 99% ad-free. Only for YouTube do I switch to Brave Browser.

I use Firefox on other devices and use the sync functionality so prefer to use it where possible.

My home router (Draytek) is also configured to force any connected devices to use NextDNS too.

Definitely worth the €20 annual subscription.

[0] https://nextdns.io