I played through
an Ibanez rg550 with EMGs, tube screamer, and marshall 2204 half stack for a decade (the 80's), and never touched the knobs - I even got them moved to be further away from the strings so my hand wouldn't keep hitting the volume knob. Recently, my main guitar is
a gibson sg supreme, with a volume and tone pot for each pickup. I also have a few smaller amps, some of which don't have many features (like just a volume knob, for instance) -- I found the electronics and pickups on the sg to be very good, and along with the amps, some of which are trebly, the knobs come in handy.
I remember back in the day, a more experienced guitar player told me I should have backed off the tone knob a little on the ibanez, because I was searing everyone's ears off in the clubs we were playing. I ignored it, but looking back he was probably right.
When it comes to recording, though, the eq you can get later down the signal path is probably much better than what you can do with that tone knob.
I've found that the usefulness of the volume knob is highly correlated to the quality of the pickups -- if they're good (rich dense tone, if you call that good), you can get a lot of variation out of tweaking it, but if they suck, or they're only about high output, then it's pretty much just for shutting them down.