Cars being online has some tangible benefits in that they can transmit location data to emergency services, especially if the driver is unresponsive. Might save someone from dying in a ditch in the middle of nowhere.
Arguably, some of the data collected while driving is also very useful for maintenance and development (e.g. if a lot of vehicles start having a similar issue after X miles).
That said, this data should be limited in scope and use (e.g. must not be sold, especially not to insurance companies), as well as anonymized as much as possible. Which is currently not the case, and that definitely needs regulation.
Other cures include literally just restarting your PC once a month so it can install updates.