Good observation. Although the question probably could be better phrased. For someone with one of those older models, how does the new machine compare in value to those older models?
That is an excellent question.
The question becomes, is the software catalog you have presently all M1 compatible and capable of taking advantage of the M1 modifications. If not the main take away of the Apple new models is the longer battery life unless as they say you get a model which supports 4 displays. The lack of Boot Camp support is likely to hold a lot of people back.
https://discussions.apple.com/docs/DOC-2741
But if that's not a big deal breaker and you can afford it, the new machines do pack a lot of punch for a small space.