On an Android phone, you can use AdGuard DNS-over-TLS server to block ads system-wide even on mobile data. Or install a browser that supports extensions or has a built-in ad blocker.
On an iPhone, you can also use the DNS method, but Safari supports extensions so you can install a proper ad blocker as well.
Tbh it’s probably been a decade since the last time I looked into it. Glad to hear some ad blocking is doable on the iPhone. Certainly I use an ad blocker everywhere else. Will see what’s available. Thanks!