Let's not pretend that Apple is the only company that people buy from to signal an in-group status.
I believe people also buy old thinkpads, dumb phones, android phones, and use Linux (arch btw) to signal to fellow nerds on the internet that they are not sheep and are more tech literate than the average person.
The SE has a button at the bottom and it is the entry level product: I don’t think most people in the US would call it a luxury good. I expect the majority of SE customers buy the SE because they want an Apple but can’t afford something better (product price discrimination), with many other SE customers wanting something cheap and not sensitive to fashion (the SE looks outdated). Of course, there are some other SE buyers for other reasons (size, like the button, less stealable, etcetera). A very useable Android is still cheaper (although obviously not the flagship models as you point out).
I believe people also buy old thinkpads, dumb phones, android phones, and use Linux (arch btw) to signal to fellow nerds on the internet that they are not sheep and are more tech literate than the average person.