I also love the posts by the low earners. We started out as 'old' by standards of FIRE, and also low-er (though certainly not low) earners...household income just above the median. Now we are high-ish earners (though not particularly so compared with this board, where there seems to be a lot of people now earning household incomes well above 100K). I try to maintain somewhat of the mindset of our student and lower earning days and the low income posters help me do that. Plus, I enjoy their creativity.
As several others have mentioned, the most valuable things I learned from this board were 1) the concept of not falling into hedonic adaptation (we've done a good job with that, I think...very little increase in discretionary spending in the past 10 years, though overall spending increased at one point as we took on support for another person in a separate house). But we just kept ramping our savings as our income increased, and this forum kept me in the right mindset to do it. 2) 'Circle of control'. I'd never heard of it before, and adoption of that philosophy has helped me dramatically decrease my levels of anxiety and mild depression.
I don't generally find the changing make-up of the board disturbing (though I do miss Sol), but I do find it pretty funny when I see threads devoted to cars and other high dollar 'hobbies' on this board of all boards, or the influx of newbs that are speculating in crypto or what-have-you. Even as someone who doesn't care much for biking and is not going to adopt biking as a substitute for driving to most places in this particular city (I know multiple people who've been killed or injured while biking locally, far more than I know people who've been injured in car accidents, + I also was permanently injured when I was struck by a biker in college), I still really appreciate a community that causes me to really question the value of my car and driving it. Before hanging out here, I might have fallen into the common practice of getting a new(ish) car every 5-10 years, whereas now we aim to get 20 years out of each car that we've bought; and I've been far happier as a 1-car house than I would have ever expected 20 years ago. And I've shifted to walking (and occasionally biking, in very low traffic areas) to places much more than when I started hanging out here. It never occurred to me in pre-MMM era to just walk or bike to my local drugstore or grocery store to pick up a few things that I need, which I commonly do now. Not that I objected to the concept of walking; it's just that I was raised by people who would drive 500 yards to get a pack of cigs from the quick-e-mart...the point of having a car was to use the car, according to how I was raised. It also wouldn't have occurred to me to plan multiple errand runs on the same day, in a clockwise order around the city so that I would spend the least amount of time and gas/idling/carbon, rather than just running out on impulse to a single store across town when I decide I need something. Likewise, I never shopped in bulk or on sales at the grocery store until hanging out here (I never even knew what those grocery store flyers were for b/c I never glanced at them). Overall, this place has made me a lot more mindful of concepts about value-per-dollar and value-of-time and how a mismatch of those things is often pushed by American culture, to the existential misery of many of us.
There have been a lot of little things like that this place has brought to my attention and kept 'in front of me' so to speak, and I really appreciate that. Consumerism in pursuit of happiness rarely works, and this place keeps that front and center for me.