“Thereafter, only Manifest V3 extensions will be supported in Chrome, a change that critics fear will hobble the add-ons and make them little more than toys.”
Google calls Manifest V3 more secure, performant and privacy-preserving. The uBlock Origin developer warned in 2019 that it would break his extension. Google has also told investors that ad blocking threatens its revenue. The company that profits from ads just set the date to rewrite the rules for the tools that block them.