Speaking for me personally…

I’ve got two main DAC/Amp combos: Ferrum Erco desktop and a Chord Mojo 2 portable.

I also have 15 pairs of headphones/IEMs ranging from HD 660S2 to Focal Utopia (just illustrating I have a range from mid-FI to TOTL).

I’ve also, like many, gone through many different pieces of kit over the last ten years or so. Here’s what I get out of my DACs…

Improved sound is for real IF you have the right headphones. People talk a lot about pairings, and comparisons can get pretty intense, but in my experience, generally, the higher in tier you go on headphones, the more likely you are to hear very subtle differences in DAC quality. These usually aren’t big noticeable differences like obviously noticeable frequency response differences but could be things like slightly more space between pieces of the mix, better imaging and staging, higher resolution, more natural timbre. I can notice these things more easily (though still with focus) on something like the Utopia or D8000 Pro than the 660S2.

Features is also legit. One of the reasons I love the mojo 2 is the exceptional EQ. This has enabled me to take even over ears that need decent power on the go and still be able to EQ them (the mojo EQ is far better then EQs you find on places like Spotify and Apple Music, etc.). This is a feature that mattered for my particular situation, but as you can imagine, there are many.

Collector/brand/emotion/design - some of us just have a passion for this hobby and trying different kit or want to support different brands, and/or yes, artistic/personal expression (even at a price).

My 2 cents. Enjoy the journey!