Isn’t it overall good hygiene to have different accounts for different purposes ?

When switching Google accounts you’ll probably don’t want it to have permanent logging cookies, especially if you’re in a pinch and not in the appropriate context (e.g. looking at your family mail from your work computer to quickly get an important message)

Putting the data management responsibility on the user is kind of a dick move, at the same level as all the opt-out garbage we have to deal with.