Define better? A Tesla will do exactly the same thing[1] and just nag you every few minutes to tug on the steering wheel (those nags are getting rarer every release as the driver monitoring camera improves, FWIW). The Mercedes driver can have their hands doing other things, but still needs their eyes out of the cockpit because the second traffic speeds up to 40mph they need to take over.
In practice, this is "Level 3", but only within an ephemeral subset of driving conditions that aren't going to be consistent enough for you actually exploit that autonomy.
[1] Actually much more, obviously, but it at least does this.
Those millions (especially in developed countries where the per capita number of accidents is highest) won't be able to buy Teslas anyway.
Statically you could decrease the number of deaths by 20-30% by just banning cars older than 10 years. There are some other (cheaper) things that can be done as well.
In practice, this is "Level 3", but only within an ephemeral subset of driving conditions that aren't going to be consistent enough for you actually exploit that autonomy.
[1] Actually much more, obviously, but it at least does this.