My 2 cents, from an audiophile who has chased the best sound that my money can buy (and that ain’t much money at all) for over 50 years.
Headphones likely will never have the same physical, visceral impact on your body that speakers currently provide (but never say never). But the tradeoffs are worth considering, and for some of us, they provide a better solution than speakers, which have their own limitations. Clearly a benefit of listening to music via headphones (primarily closed-back models) is the privacy of listening without interfering with the people around you (and the isolation from the people and sounds in the environment around you) has value to many, as does portability of the listening space, which brings with it a known acoustic environment wherever you are listening. For many of us, a big part of the attraction is the ability to get high quality sound for a good deal less money. High-end speakers can cost as much as a house; while stratospherically-priced headphones are a fraction of that. Good sound from speakers requires good amplification, which can also expensive. Good cans benefit from good amplification as well, but it comes with a much lower price tag. Both of these listening modes require cables, but speaker cables are more expensive than headphone cables, and you generally need many more feet of speaker cable. And then there are the vibration isolators for the amps, speakers, and peripherals, as well as the power conditioners and all the other voodoo and black magic that many hobbyists find to be necessary. Again, similar tweaks exist in the world of headphones, but they can be had at a significantly lower cost.
Seriously dialing-in speakers also requires acoustic treatment for your room, and after you have done all that, you likely are left with a sweet-spot that is very small, meaning that, to fully receive the best that the speakers and system have to offer, only one person in the room can hear that level of refinement at a time. This, of course, is true of cans as well - but cans don’t pretend to be anything other than a personal listening experience.
I concede that the social aspect of listening to music is a great value that speakers provide, and one that headphones simply cannot. However, if you want to listen critically to music presented by your gear in the best possible manner, for many of us that becomes a personal experience anyway.
In the end, I can hear music presented in a manner that approaches the best sound quality available from speakers in a more affordable manner with headphones, and that experience is not limited to the sweet-spot chair in my listening room. I have discovered so much detail in my music collection listening to headphones than I ever did listening to speakers. I believe listening to music through speakers is a great and unique experience, but I also believe you hear a good deal more in the music when you listen through headphones.
