Brand loyalty is for suckers. But it's what brands prey on. They foster brand loyalty. And unfortunately there are a lot of suckers.

I think it comes from Depression era kids who found a brand that didn’t create cheap junk and so they spread the word. But of course, that has been co-opted by capitalist pirates who buy a brand famous for quality, gut expensive manufacturing with the cheap alternatives and then count on making a profit before word-of-mouth catches up to them.

Sears retailer. Gibson guitars. Off the top of my head. Thousands more examples over the years.

My guess as for why people do it today was because their grandparents or previous generations did that as a survival necessity but now we are seeing the behavior warped from its original purpose. Like opening and raising your right hand to show you had no weapon became a friendly wave hello nowadays. Maybe that’s not an analogous example but you should get the idea.

Allegedly they used to, but Musk felt that vision should be enough because humans don't have radar either and they're just fine.

https://www.drive.com.au/news/elon-musk-overruled-tesla-engineers-radars-cameras/

LIDAR generally works better at relatively short distances (like less than a km). Several other car companies are going with LIDAR and do alright. Musk thinks cameras with image recognition would be sufficient without anything else. It goes without saying that Musk is very wrong.