also, duckduckgo browser recently started a beta for their in app, systemwide ad blocking, you just have to download the browser and apply for the beta. I don't use it (nextdns) but I wanted to mention it here for others
In my opinion the best and the cheapest (free, lol) way to block ads on phone, and mb on whole wi-fi spot is to use pi-hole.
If you don't have raspberry pi, or don't want to install you can you it on your old (not too old tho..) Android phone.
Pi-hole + Unbound for Android · The DNS Ad-blocker made for Raspberry Pi works great in Android · Linux Deploy image for rooted Android 4.0.3+ ARM devices. - GitHub - DesktopECHO/Pi-hole-for-A...
Just tested, works good. Root your phone, install pi-hole by guide in readme, set DNS in DHCP on your router to local address of your Android phone and forget about phone, leaving it plugged into the wall.
By using web ui you can configure so much filters as you want.
You can also combine it with dnscrypt-proxy in termux. Download android bin from releases, chmod +x dnscrypt-proxy, change dnscrypt-proxy.toml to your requirements, mandatory step is to change listening address port from 53 to one you like, I use 5354. After that execute, go to web console, set custom DNS to 127.0.0.1#5354.