adguard - free and open source content blocker. you need to pay premium to add custom lists, but their built-in lists are good enough that I don't need it. manually entered filters are also supported.
if you use apps, it might also make sense to get a VPN based adblocker.
AdGuard Pro adds DNS-based blocking via VPN, in addition to browser content blocking. It also logs tracker requests. The DNS-based blocking works on all apps, afaik.
There's no uBlock (assumedly Origin) port to iOS, because browser extensions are not permitted on iOS, and they don't allow other browser engines so every alternative browser is a Safari skin. You can't just install Firefox to get around that restriction.
IOS does have native content-blocking, which is reasonably effective but nowhere near uBlock Origin. It's similar to the manifest v3 stuff where Google is castrating Chrome. And yeah there are tons of them available for free, which makes sense because they're all just using pretty much just using Easylist[1].
I use 1blocker but its a paid one - there are a bunch of free ones as well but I got bored working out which ones were scammy and 1blocker (at the point in time I started using it) seemed not to be scammy.
A really robust option that will work on all of your devices is to setup a remote Pi-Hole and access it via VPN. (This last point is very important and I learned the hard way after my publicly available Pi-Hole instance was discovered and used for DNS amplification attacks.)
I recently went on a journey of setting up a pi hole. I eventually gave up and set up NextDNS instead. I didn't want to have to use a VPN for everything.
I was previously using Adaway on mobile. I think NextDNS produces the same result.
if you use apps, it might also make sense to get a VPN based adblocker.