You basically have it, uhh, right on the money, so to speak. I think a lot of other people try to make more specific, scientific definitions, but once you get into the meat and potatoes of, what is a “necessary” expense, what is a reasonable amount of comfortable savings, yadda yadda, you start to see the cracks form. Realistically the only solid definitions that I think I’ve ever seen have mostly just been made on the basis of people not having to work at all, to live, vs people who have to have a job. There’s probably a very highly qualified definition of “middle class” out there, but I’m not sure if it would match the idea of “middle class”, and if it would also illustrate anything valuable for anyone, really. Especially if you’re going based on the former definition of “needs to work to live”, then most middle class definitions you’d come up with would probably also fall into working class.
I dunno. It’s interesting to me how many people kind of get caught up on what I see as semantic arguments, rather than analyzing arguments around like, oh, do we like a capitalist structure of ownership, like a corp, or do we like a worker structure of ownership, like a co-op? It hits me as being a very kind of moralistic argument about “leeches” and “capitalists not contributing to society”, when really I think we should be caring about what’s a more ideal/efficient way to live, rather than caring about, you know, whether or not somebody should be defined as middle class, or petite bourgeois, or whatever. It’s basically the same argument either way, but I find the framing to be pretty important, and often overlooked.