Why would Google be given any benefit of a doubt in the case of ad/resource blocking?
They are a behemoth ad-based corporation that is becoming a monopoly in many areas of computing. In yet more areas, they are becoming an effective monopoly through size: they may not be the only company offering a type of service, but they are the only one able to offer it at scale and/or with a certain level of sophistication, given their resources are orders of magnitude larger than almost any other company's.
All this taken into account, it's obvious how much is at stake for them. Why wouldn't they try crippling blockers? Their revenue depends on it and the only counter-incentive is that there may be a massive exodus of users to Firefox, while it still exists. Do it slowly enough, though...
A design that happens to cripple modern ad blocking and is not nearly close to being a full replacement of the existing API. Improving performance by removing features is easy. I don't think it's misrepresentation to call it crippling of said features.
The fact is that modern ads and crapware/malware web resources are a large problem that users choose to deal with by installing modern ad blockers. Even if that makes the browser somewhat slower overall, it is the ads that are the culprit, not the ad blockers. Also, anecdotally, but I find the web's performance to be vastly improved by installing uBlock Origin, as has also been noted in another comment.
It is also a fact that Google's whole business revolves around ads. Again, why wouldn't Google be mindful of ad blocking and try to prevent it from happening, with all the resources it has at its disposal? It would be bad business not to try.
Even if this particular situation isn't an example of this, I think it is irrational to think it does not and will not happen.
They are a behemoth ad-based corporation that is becoming a monopoly in many areas of computing. In yet more areas, they are becoming an effective monopoly through size: they may not be the only company offering a type of service, but they are the only one able to offer it at scale and/or with a certain level of sophistication, given their resources are orders of magnitude larger than almost any other company's.
All this taken into account, it's obvious how much is at stake for them. Why wouldn't they try crippling blockers? Their revenue depends on it and the only counter-incentive is that there may be a massive exodus of users to Firefox, while it still exists. Do it slowly enough, though...