I suspect only a small subset of people who generally run an adblocker also block ads on apps as it requires a lot more specialized knowledge.
Settings -> Network & Internet -> Private DNS -> dns.adguard.com
Now you've blocked a large percentage of ads on android.
Not always, though. For instance it won't work on YouTube ads. I'd call it a hack at best.
I'm sure you're already aware of this, but for other HN users on Android, ads on YouTube are blocked when using Firefox Android + uBlock Origin + m.youtube.com -- the experience isn't as nice as the app but still totally worth it IMHO.
Use Youtube ReVanced if you want the full app experience.