I think it is an over-statement to claim that "Most modern cars come with similar collision avoidance systems."
Many have collision WARNING systems (i.e. no auto-braking), and even then only on the highest trims or with an expensive options package ($3K+).
However collision avoidance systems do exist, and manufacturers like Subaru have made them so inexpensive that there's little excuse to not buy it (e.g. Subaru Legacy Premium W/Eyesight is $25-26K, similar to a mid Camry or Accord, and those lack CAS at that price point ($30K+ Limited trim to get CWS in other cars, let alone CAS)).
Aside from the luxury market (which Tesla is in) a lot of cars lack CAS or make it so expensive that they may have well. Subaru is the only manufacturer that makes it within the realm of your average joe (e.g. sub-35K).
Many have collision WARNING systems (i.e. no auto-braking), and even then only on the highest trims or with an expensive options package ($3K+).
However collision avoidance systems do exist, and manufacturers like Subaru have made them so inexpensive that there's little excuse to not buy it (e.g. Subaru Legacy Premium W/Eyesight is $25-26K, similar to a mid Camry or Accord, and those lack CAS at that price point ($30K+ Limited trim to get CWS in other cars, let alone CAS)).
Aside from the luxury market (which Tesla is in) a lot of cars lack CAS or make it so expensive that they may have well. Subaru is the only manufacturer that makes it within the realm of your average joe (e.g. sub-35K).