Firefox with the built-in "Enhanced Tracking Protection" gets you about 70-80% of the blocking that a dedicated adblock system can, depending on the site, and at least saves you from some of the worst behaviors. Between that and network-level ad blocking (Eero+), I really only see first-party ads like FB/IG. When I'm not at home, the chances are pretty low that I'm just casually browsing the web rather than using a dedicated app (where I probably bought or subscribed to avoid ads).
Edit: and if you're willing to use Safari on iOS, there are dozens of Safari plugins on the app store that provide good-enough adblocking.
