I would argue that that depends on your architecture. If you gather more data than you data storage can handle and it starts slowing you down your core product

I would argue that that depends on your architecture. If you gather more data than you data storage can handle and it starts slowing you down your core product then you should stop. But if you that is not a factor then you could collect as much as possible and later decide whether it was or is worth collecting UNLESS it starts raising privacy concerns if you have a user driven project.