Google is proposing a broad set of changes to Chrome’s extension platform, called Manifest V3, the arrival of which we’ve been expecting since late last year. Among other things, Manifest V3 will stop most ad blockers from working as they’re currently able to. Today, ad blockers use Chrome’s “webRequest” API to block certain HTTP requests from ever being made at all, but Chrome needs to check with each relevant extension before processing a request. This adds a (sometimes significant) delay, which Google is trying to avoid.

Under the proposed new design, Google Chrome ad blocker extensions will be forced to use a new “declarativeNetRequest” API which is styled after Adblock Plus’s blocking method, and is limited to 30,000 rules (EasyList alone is well over this 30,000 limit). Beyond that, by styling like Adblock Plus, other ad blockers like uBlock Origin which work on a different system are prevented from working as intended.

In other words - it is issue as people hate ads, and even now google pays and push hard, but still many extensions block ads they want to show to you.