Audiophile equipment is full of placebos and scams. But there’s also a lot of very real improvements. I would also say the majority of people are well before the point of diminishing returns but hey.
One big problem is that the source of your music often is the limiting factor. A lot of music sounds not so great on my nice headphones. .Likewise, the songs I really appreciate on my headphones, tend to sound like mush on shitty speakers. That doesn’t make either music bad, they know their audience but If I didn’t like much of the hifi music then I probably wouldn’t care much about my sound setup.
I think like most things there’s a balance to be had. Obsessing about the little stuff can often get in the way of enjoying it, and be a massive waste of money. But I also wear headphones for 10+hrs a day, it’s worth investing in them.