Yeah, another aspect here is optimizing tests properly. Of course, this also takes engineering time, but if you get your performance culture in the right place, hopefully test run costs can be commensurate to the amount of value you're delivering. That will allow you to never have a situation where your tests take inordinate amounts of time because you cannot afford resources to run them.

Everything is tradeoffs, of course. You have to decide what's right for your business. But I think it's rare that there is too much or too thorough of testing. I'm guessing most orgs err in the other direction.