I've been speaking to friends working at different companies across the self-driving industry, and almost all of them have their fair share of skepticism of L4 or L5, including those who are actively researching in the field.

The main reason for this is that current self-driving tech has plateaued with most companies going with the redundancy based approach (let's have 3 LIDARs instead of 1, and make that 4 IR sensors on each side instead of 2 etc.) simply because there is no revolutionary new tech that is a panacea to current L1 problems.

Sadly, explaining this to investors is next to impossible, so everyone keeps selling the same idea with a few more whistles as the next big thing while everyone is waiting for the big tech breakthrough that makes actual self-driving cars possible.

Until then, expect many more controlled environment (eg. airports or freeways where traffic is mostly smooth flowing, or roads with perfectly marked stop signs and pavement paint).