[LiamPowell]

Most ad blockers do already use MV3, uBlock Origin is the only one still using V2 as far as I know.

There are some drawbacks to V3, however none prevent creating an effective ad blocker, as demonstrated by the fact that many exist. Though saying that doesn't make for nearly as effective clickbait...

[63stack]

If this is clickbait, you are a google shill. The limitations of v3 are very clearly explained on the ublock homepage:

uBlock Origin used the webRequest API to intercept and block network requests in real-time. The replacement declarativeNetRequest API has hard limits on the number of filter rules (previously 30,000, now 330,000) and lacks the dynamic filtering capabilities that made uBlock Origin so effective.

    Cannot use all filter lists simultaneously (rule limits apply)
    No cosmetic filtering in the default mode
    No scriptlet injection by default
    Limited dynamic filtering capabilities
    Requires broader host permissions upfront

[krackers]

The part no one gets is that mv3 by design cannot do privacy protection by stripping tracking tags. Any sort of programatic URL manipulation or introspection is impossible by design. Advertisers can switch to a scheme of base64 query params inside URLs, and there's nothing MV3 based adblockers can do to filter this