The problem with this, and a lot of other analogies comparing the car industry with aircraft manufacturers is that you end up with an apples-to-oranges comparison
It is in the nature of a
analogie not to treat equal things, otherwise it would be a simple comparison. Analogies are used to clarify a idea or thesis. The setback is that people who don't want to understand will always bring up the apples and oranges.
As I said before, modern technology meant that engine control no longer required a physical connection between levers and engines for throttle control - in fact statistically it behaved more reliably than the old arrangement, simply because digital control is not subject to physical entropy through wear and tear in the same manner. To backdrive the levers would require an artificial force-feedback system that would not only incur a weight penalty, but also compromise the simplicity of the system, incurring a maintenance cost penalty as well.
A equally modern design (777) has just as little physical connection to the engine. But you pointed it out nicely: It must be the cost penalty that inhibited AI engineers to consider the backdrive depriving us of a (my interpretation) extremely useful feedback in case of screw up or confusion (as in this incident).
Just to comfort you: When I flew a MD product I was heavily involved in a fervent criticism/discussion about a lack of design/checklist. It has nothing to do with anti-AI feelings. I simply strive for the best pilot-machine interface available and strongly believe that the throttle design with feedback from autothrottle commands is safer than the one without.
Safe flights
GMDS