People don't really use old-fashioned graphic equalizers anymore, they use digital parametric equalizers. Some AVRs have such EQ systems built-in, but you can also get an outboard EQ like this in the
MiniDSP among other processors.
as for over-processing, yes absolutely people over-process their sound. I would argue that room-correction equalizers such as Audyssey, MCACC, YPAO, etc, are badly overused. The more that I learn about it, the more it looks like an audio plague. I would bet they are causing a lot more damage than any help they are providing.