I find configuring an ad blocking private dns over https DOH in Firefox much faster and efficient compared to other methods. Firefox Extensions and VPN add unnecessary over head.

If interested, the steps are documented in my notes - https://abskmj.github.io/notes/posts/android/firefox-dns-https/

If you don't mind paying, Blokada has a "cloud" subscription. You set your DNS settings on the phone to what they give you, turn it on in the app once, then it runs without using the VPN method.

I use it because, even though it's another God damn subscription, it seems to work better for me and now I don't have to think about it.

Setting up a PiHole is a method that should work. Costs a bit if you don't already have something to host it on.

Pihole + firefox + ublock for adds here. Im not using this, but its also possible to set your home server connect to VPN provider and then route all traffic through that. Then you can use your selfhosted VPN to connect with phone and use both at the same time. Or just enable add blocking on your VPN provider, I guess most of them have one

I use the Samsung browser with the Adguard plug-in, which works great with customizable filter lists.

Samsung browser: https://play.google.com/store/apps/details?id=com.sec.android.app.sbrowser
Adguard for samsung browser: https://play.google.com/store/apps/details?id=com.adguard.android.contentblocker

I recommend cromite's (fork of bromite) adblocking. It works well and I don't see ads (at least the big ones, maybe I overlooked some smaller ones)

Personally I use my own selfhosted AdGuard Home instance, configured on my phone as the private DNS server, therefor connecting via encrypted DOT. I've also got this server configured as the DNS on my home network router, meaning every and any device in the network profits from the adblocking, no matter how the respective DNS is configured. If you dont want to mess around with linux, docker and selfhosting in general, NextDNS seems to be a very valuable option as well. In any case, this is a lot more efficient than having an adblocking extension in your browser, since AGH/NDNS will also block ads and tracker in any other app that isn't Firefox.

Im not very familiar with Opera but do you have the "Allow Acceptable Ads™" setting still on?

Edit: I just used an ad block testing site with Allow Acceptable Ads turned off and tracker blocking and the score it got is about the same as firefox mobile with ublock

If you don't want firefox, Cromite is pretty good. Also if you need your vpn for other things, then the next best thing is a custom dns, I use nextdns which is customisable and blocks a fair amount of stuff.

Iceraven

Confused why nobody has mentioned Brave Browser. Never had issues with speed or ads.