Mobile chrome. Not sure if there is even an option for an adblocker here. I used to just have a PIA VPN always enabled with the built in ad killer, that worked well system wide but it kept tripping up my bank apps so I stopped using it.
On iOS you can use Adguard Pro which works with all browsers (I use this) https://apps.apple.com/us/app/adguard-pro-adblock-privacy/id...
Not for everyone I guess, but I haven’t perused the privacy policy in great detail.
Not as powerful as UBO but you can use it on almost any device.
Highly recommended