Xtreix Vanadium has a proper network-level ad blocking implementation. It does not have complex dynamic rules or cosmetic filtering via CSS at the moment. YouTube ads can't be blocked with declarative network-based filtering but rather require invasive changes to the site which are regularly changed to keep up with it changing.
Firefox doesn't support sandboxing on Android and using a fork of it doesn't change that. It doesn't enable a sandbox since it doesn't have one, let alone the 2nd layer of sandboxing offered by the V8 sandbox and modern exploit protections.
Velocity9490 Vanadium has a real adblocker. It does not have injection of JavaScript and other dynamic features required to bypass YouTube ads.
Laurent DNS filtering can't block YouTube ads anymore. It will eventually likely become impractical for extensions to reliably work around it without getting blocked.