Headphones

Never tried 6xx but wasn't a fan of HD650 compared to DT880.

No doubt they're competent, but the snowball effect of being a common first foray into hifi, the praise/purchases driven by internet popularity have probably placed them on a bit of a pedalstool.

Not liking what is most popular doesn't mean you lack an ear for hi-fi. Personally if I consider the harman curve or FR tunings/eq profiles created by popular community authorities what is popular often sound dull, stodgy and bloated to my ears.

Well, something to know is that the HD6XX and all the other HD600 variants are headphones that are very good at producing super intimate vocals. So if you listen to vocally powerful or emotional music, you may be thrilled with them. Give the James Bond track “No Time To Die” a listen for example, should be really good on your 6xx. But aside from stuff like that, anything that needs bass or is primarily instrumental will suffer from the fact everything else is pulled back to focus on the vocals. Soundstage is narrow mainly just in your head and next to the ears and imaging is very limited to only a few directions on those so gaming won’t benefit and nor will many recordings with vastness to them. A better look into hifi especially right now with the deals on Amazon are the Sennheiser HD560s which is a relatively flat and high resolution sound or the Sennheiser HD599 which is very similar but with just a tinge of fun with a little more bass and mids (the 599 is real good for rock but will cover any genre naturally and beautifully) These also add some soundstage and imaging so they are a more complete test of whether or not you appreciate Hi-Fi.

The HD6XX just isn't that good, in my opinion. I had it for a while and tried to make it work with several DAC/AMP combos and it's just dark and subdued to me. You should get rid of them and try something else.

As for your question, most people get into hifi because they want to hear music in an ideal way and that desire is worth spending the time and money on.