I recently did this with openvpn+Pi-Hole running on a NATted £4/year VPS. It's great to have DNS blocking for your phone's apps and so cheap I'll setup another one for redundancy at some point.
OpenVPN on Android lets you select apps to bypass the VPN, so I have a second browser on standby if I ever need direct internet access. Or I could use the disable for x minutes feature of pi-hole.
Where can I find a £4/year VPS?
https://lowendspirit.com/
Proper ipv6, shared ipv4 with a port range forwarded for you to use.
Bandwith allowances seem far too low for use as a VPN or proxy server though?
I'd wager that quite a few people would like to pay for a managed VPN service that did the same thing.... however, as once in a while you need to disable your adblocker on some websites, so once in a while you might need to circumvent the blocking on the VPN. I wonder how that might be done.