I'm really not sure what kind of changes you're talking about. They certainly don't do what you describe at the API level. Maybe you're just talking about bugs?

I'm really not sure what kind of changes you're talking about. They certainly don't do what you describe at the API level. Maybe you're just talking about bugs? I have encountered a few browser regressions over the years but they're always for really exotic use-cases of relatively new APIs, and they always get fixed in the next release. I've been working on a suite of highly complex JS-heavy tools for the past 2.5 years, and the problems that have stemmed specifically from browser bugs in that time are a vanishingly small number. Probably less than five.