Isn't it concerning that Tesla has 500 million miles of driving and is still L2, when Waymo is at 20 million and they're at L4?

Maybe Tesla's approach isn't the way to go.

The company decides the level. Tesla's approach is to get more real-world training data to reach a general solution, while Waymo goes slow with pre-mapping as a requirement.

Tesla's approach will likely be the winner long-term and can be flipped on globally far faster than Waymo's could

Everyone’s working on a general solution, including Waymo. Everyone has large real world (and even larger simulated) training data. It’s not just Tesla despite what is widely claimed in Tesla circles. Others just choose to deploy in certain places because of market, operational and safety reasons. This notion of Tesla just ingesting training data which magically outputs a general self driving solution is nonsense.

The levels aren’t just slapped on by the companies for vanity. They indicate liability and therefore capability.

I said approach, not vanity. Having 200,000+ safety drivers across the U.S. and classifying it as level 2 is Tesla's approach.

Waymo's approach is a Level 4 system from the start, but in a very limited operating environments, and slowly expanding.

They're classifying it as level 2 because that's all the system is capable of. You can choose to call it an approach, but it's really an indicator of capability.