They already are worse.

Smartphone OS makers have top-notch security teams, and they are tech companies who understand how tech works extremely well. Actual Android smartphone makers (thing Samsung or Motorola) are humble enough to understand that they should just let Google do the hard parts of the OS.

Car makers are not tech (software / internet) companies, do not understand how to think about tech to be successful in tech, do not have the right mental models for cybersecurity work, but they nevertheless want to do their own software instead of getting it from a more responsible party. This is a recipe for disaster. And, just like smart TV makers, they make their money on hardware, compete on price, and aren't advertising companies themselves, which encourages shady deals with data brokers.