It depends on who “you” are in this case. If that “you” is a company that solely makes money by selling various behavioral data and has little care about variou

It depends on who “you” are in this case. If that “you” is a company that solely makes money by selling various behavioral data and has little care about various jurisdictions (which they really should, especially with GDPR, let a long “doing the right thing”), it might very well be useful to collect extra signals. However, if “you” is a company that is in some other business, but collects analytics for the purposes of optimizing it’s product and figuring out what actually works for their users, then you don’t event want to run the risk of ingesting something private. Especially with exposure to different jurisdictions. Think of it as the difference between a double-opt-in email list where you are very sure people want to receive the communications and an unsolicited spam list. If the user volunteers this data and it has some relevant business purpose, that’s great. However, if the user doesn’t know I have this info and wouldn’t want me to have it, then acting on that data could create a lot of negative emotions that as a company I wouldn’t want.