With ”there is a VPN in F-Droid", do you happen to refer to Netguard? https://lemmy.sdf.org/comment/11993547
Netguard is a FOSS Android app which kinda works like a firewall. You can allow/block network access on a per-application basis. You can limit access e.g. on WiFi or on mobile etc. It also supports blocklists, supplementing your ad blocker.
To the Android OS, Netguard acts as if it were a VPN.
Limitations:
The app is very stable, I have been using it for about 5 years without problems. For most use cases it is fire-and-forget, i.e. I rarely open the app any more.
If you are putting the word “whitelist” in quotation marks because you understand that it might be read as a politically incorrect term, you might want to use the term “allowlist” instead.