eg Apple publishes a new ios rev; debugging on it requires upgrading xcode; and that requires updating your OS.. Good thing you don't mind wasting a full day or more reinstalling every other devtool you may happen to use. Or xcode just doesn't connect to your ios device because reasons. (The reason is apple writes shoddy slapdash software because monopoly.)
So now you're spending another $1500+ on a studio so you can do all this in VMs and see how bad the damage will be to avoid blowing up your main devbox. etc etc.