I'm glad to see someone making this for Chrome. I really like how Safari does
it. It can check mail and messages, then delete the message after verifying. One of the reasons why I am finding it difficult to switch from safari.
I use Safari almost exclusively for all desktop browsing, and haven't seen fully broken or even mildly broken websites in years.
I think what helps a lot is that if it's broken in Safari on macOS (not a big deal for the business), it would also be broken in Safari on iOS (which would be a disaster).
Most of my experience with broken sites are from media extensions for javascript that just are not available to anything other than Chrome. These may be niche, but that is my world. I don't use Chrome, so I'm kind of used to seeing these. Again, these may not be in the wild on sites with large visitor counts, but I have had to decide on not using certain things because they are not available in Safari/Firefox.