You'll find that indeed most manufacturers offer AEB, forward and rear collision avoidance, many of them offering side collision detection. Subaru, Volvo, Toyota, Audi, Mercedes, for ones I know for a fact. I'm more unsure as to why you think other manufacturers don't do these things.

Someone who hasn't bought a new car in the last couple of years probably wouldn't be aware of these features. Also for some reason car dealers, at least in the US where I've been buying cars recently, don't seem to highlight these features too much. Perhaps because they're not a way for the dealer to make more money. It can also be quite hard in my experience to get a straight story on exactly what the safety capabilities of a given car are. E.g. will it just warn of an impending collision or activate the brakes? Does it drive the steering system on lane departure or just warn? When buying a car recently for my new driver son to drive I had to pretty much try driving it into things to verify the features were implemented as expected and in one case (active steering on lane departure) I didn't know the car had the feature until after taking delivery.

I think a lot of car sales people are tech-averse and simply not interested in, or prepared for dealing with the faster consumer cycles of cars.

I recently did a test-drive and the guy maneuvered the car out of the dealer lot by driving backwards and looking out the rear window, completely ignoring the fantastic surround camera and sensor view that popped up on the huge display in the car... Great job selling that feature, buddy.

One reason is that other manufacturers are extremely conservative when it comes to the marketing of these capabilities, in comparison to Tesla who is overpromising a lot.

Another reason is that Teslas are "cool", and get a lot of press in non-automotive circles, which means that a lot of people think they were first with a lot of technology, which simply isn't true.

And a possible third reason is that quite a lot of tech people have been researching and toying with the idea of getting a Tesla, but those same people have never researched similar vehicles from other manufacturers, so they have no idea how they compare.

I had a 2014 Mercedes E-class, its self-driving capabilities was on-par with a 2014 Tesla. However, Tesla offers over-the-air updates of their vehicles, so existing Teslas got better, while my vehicle stayed the same, so that's a point they should have credit for and something they actually do better than most other manufacturers.

Individual reports are not data.

https://www.iihs.org/topics/advanced-driver-assistance

"study found that systems with forward collision warning and automatic braking cut rear-end crashes in half, while forward collision warning alone reduces them by 27 percent. The autobrake systems also greatly reduce rear-end crashes involving injury."