Motley, what happened? I find myself agreeing with you!  Certainly 2020.
However, regarding the problems of the "American System" I can't say the Parliamentary system is necessarily better, though it may seem so at the moment.  It may depend on the situation, and there's always the delicate balance between stability and flexibility -- frequent governments rising and falling  isn't productive and can lead to extremism.

And then there's the question of multi-party vs. two-party.  Again, it's easy to think the votes are greener on the other side of "the Pond", with some  having multiple parties--this leads to more expression of minority positions -- good-- but sometimes chaos as well.

And what about the Electoral College vs. popular vote?  Currently popular opinion, especially  among Democrats, is strongly against the EC, but we can think of other situations where we'd prefer the Electoral College.
All three of these questions deserve serious debate though I don't see any as "The Key."