Very good article, pretty much gets it all.

Only thing I would question is do 1x systems really have an increase in wear of the chain and cassettes due to cross chaining ?. Not sure if this is a real issue. In ye olden dayes, with a mt. triple, you could typically use all 7, 8 or 9 of the cogs while in the middle ring without worrying too much about cross chaining and system wear. Or at least you could worry about it but the system could handle the angles without complaining. With typically longer chainstays (as compared to road bikes) the angles were not so steep and in general the system worked OK without a lot of chain drop, unless maybe in a DH race. In practice the usage tendency was rather than shift the front up or down and risk getting "caught" in the granny or big ring, as you encounter a rapid change of terrain, you would simply stay in the middle. Thus maybe the push for wider cassettes. A look at Sheldons gear chart somewhat shows the evolution of large cogs on cassettes. For Shimano systems 7 & 8 went to 32 or 34. 9 spd. went to a 36, 10 went to a 42 and 11 goes to 46. Can't say if this is a case of Shimano responding to user demand, or and as is more likely, Shimano (and SRAM) just pushes what they feel is appropriate for the users, with the result that end users see a 46 and say "I don't need a triple". Or a double.

With 1x I wonder is the 11 or 12 cassette that much wider in terms of space used on a hub, as opposed to a 7, 8 or 9 ? so as to cause much add'l system wear as compared to a 7-8-9 spd. triple system ? I believe the answer is "maybe", but does it become a common complaint from users that "my 1x system wears so much quicker ?". Certainly the cogs are spaced tighter and that accounts for no increase in wear, but the cogs are also thinner as is the chain, and that might increase system wear, maybe counteracted by better materials in use compared to 20 years ago, so that increases durability. Thus a wash overall is my take.