Even the grinder used conical vs. flat burrs and high RPMs vs. low RPMs creates palpable flavor profile differences
I bought a good grinder about 6 months ago - a Fellow. I changed nothing other than the grinder and my coffee improved. And it is so much more enjoyable to use: Less mess and static, less noise, and everything feels nice to use.
I've somewhat recently found out that I enjoy hand grinding beans and having the resulting coffee quite a bit.
There's something about the sound, the smell, and the feeling once the last bean is ground, that just works for me.
Maybe some years ago I'd have chastised my future self for enjoying something I certainly couldn't identify in a blind test, but nowadays I'm all for "whatever works."
No doubt. I found a Fellow Ode cheap, and upgraded to the Gen 2 burrs. My coffee went from a little better than 2 am truck stop coffee, to something better than you can get at a cafe.
I am using a Breville precision brewer, but would love to upgrade to a Moccamaster one day.