I specifically recommend Firefox because Google's recent changes (depreciating manifest v2) will make UBO less and less effective over time on any Chromium based browser (which is basically every browser you've heard of that isn't Firefox). So if you want the best ad blocking experience, Firefox is the only real option going forward.
iOS uses Safari for webview and does not allow any other browsers, so other "browsers" you see on iOS are just Safari wrapped in different skins. That means their usual extensions wouldn't work.
There's a system-level content blocker feature that can block ads for Safari in iOS, but I don't know if there is anything quite comparable to uBlock Origin available.