I use Blockada on my phone, which runs an adblocker as a local-device VPN; a neat trick to do this without needing to root the phone (although mine is also rooted).
Unfortunately, you can only use one VPN at a time on Android. I'm not sure how you would go about blocking ads on an unrooted phone while simultaneously using a VPN. Samsung phones do have a workaround using knox, but it requires re-generating a developer key every few months and is too much trouble for most people.
