I am saying that passively watching the road for hours on end is much harder than actively driving.
What makes you confident that you are actually good at it, and are not the victim of Dunning-Kruger? Do you regularly find yourself in the process of stopping your self-serving car from crashing into things?
Or has your car simply not crashed yet?
All the 3 of them? Among millions of Tesla vehicles out there and the hundreds of millions of miles driven? Is that even a considerable risk when compared to the general (non-zero!) risks of driving?
For me personally I simply know when I watch the road and when I don't. For some people this might be hard, for others - not so much. I am aware of when I pull out my phone or distract myself and when not.
But are you just watching or are you seeing the road? How many times have you taken control from your car doing something stupid and dangerous?
Unless the answer to that second question is 'I do it all[1] the time, and I'm batting 20/20', what makes you confident that you'll catch the next instance?
[1] If that's really the case, you should probably short TSLA, it doesn't sound like their car can safely operate.
Yes, I think I would be able to do this job safely. Not everyone has problems with focus to such an extent that you can't help but be on the phone when you need to be paying attention.
Doing that for five minutes is easy.
Can you do that for eight hours? Day after day? Without a single lapse in attention?
This is a much harder job then the truck driver has - because he constantly has to make microadjustments, to correct for road conditions.
People's brains don't work the way you think they do.