What's missing above for L3 is the Safe "Handover/handoff" period/phase. For Tesla, that period is an unsafe zero seconds. It would just suddenly alarm disable its automation at any time including when its cameras are blinded by the sun glare. Another example of Tesla's unsafe zero-second handover period is phantom brakes. Sudden phantom brakes without warning do not technically shut down the system but it requires the driver to take over and press the accelerator.
L3 must give humans adequate time to take over. For Audi, it's minimum
10 seconds and the system starts to progress to an orderly and safe emergency procedure after no human response in 20 seconds. That also means no more phantom brake allowed. "Handover" period/phase can be as long as
45 seconds to warn humans to take over soon.
Many companies do not want to sell L3 because they can't figure how to implement a Safe "Handover/handoff" period/phase such as: How can they get rid of phantom brakes, sun glares?
And if they know how to eliminate phantom brakes, sun glares (Waymo, MobilEye...), they might as well progress to L4 instead of the troublesome L3 Safe "Handover/handoff" period/phase.