Re chain angle, I brought it up thinking of chain life. I only have experience with up to 10 speed, so admit that I have no idea of how a 1x with 11 or 12 will last. Ever since way back to the 7 speed era I've tended to get 5,6000kms out of chains before they get to that wear point of 1/16 inch over 12 inches. Was probably more kms with the 7 speed, but 9 spd has been consistent and cassettes are good through numerous chain changes.
I don't know if a 1x system will wear outt chains a lot quicker.
even if so, I guess it depends on if there's a big difference. If not welll then it's not a factor really.

as for simplicity and reliability, in all my biking life, just about every gear and shifting system has been incredibly reliable, so that's not a real concern for me.

but again, if you're happy with what you use and it works, great.