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I think there would be a fairly clear line in terms of durability; so whilst a 7 speed block is more advanced than a fixed wheel, it doesn't fundamentally change the durability of a drivetrain.
Drivetrains from (9?) speed onwards has compromised durability for weight and brought little material advantages to the average cyclist. If you can't make it smoothly up a hill on 9 speed STIs, then 12 speed EPS isn't going to make a difference. Similar things with BBs, headsets, handlebar widths etc.
I don't know if it is a valid line in terms of is it a useful distinction, but I think the distinction is there.
Also @mtsdw I would theoretically suggest disc brakes, since they mean that instead of wearing out and replacing the rim you just replace the disc, but they are an ever evolving minefield of standards which is funny given the context
branwen-
Drivetrains from (9?) speed onwards has compromised durability for weight and brought little material advantages to the average cyclist.
I think one exception to that is the ability to run a 1x9 drivetrain and therefore have the weight saving and extra simplicity of not running a front mech and shifter. 1x7 would be fairly limiting in terms of ratios or would give you fairly big jumps over a wide ratio. I ride on old ten-speed (2x5) sometimes and the jumps between sprockets in either chainring is so big you sometimes have to ride it like a singlespeed i.e., the cadence is way too high or too low.
ffm
The problem with that sort of statement (same goes for the Cat 4s on 10k race bikes) is where do you draw the line, in terms of tech and budget? Within reason your choice(s) are debatable and essentially down to personal preferences. A 7-speed freewheel will seem ancient to a 12-speed EPS owner, but it's a decadent and unnecessary frivolity to someone who rides a 1940s fixed wheel machine.
I'm not completely alien to the sentiment, though, I am not that fussed about the latest kit or the inability to afford it atm, since what I have works for what I do.