Hi Drozz
There are a few still playing, it seems to be the start of a season is some of a flurry, then people either drop off, or just don't talk about it.
Diablo3 is NOT as strong as Diablo2 7 years after launch. many of the last few years of patches have been "BUFF EVERYTHING TO 11!!" so you do big damage numbers, you push into higher level dungeons, and the never ending paragon slog.
Its quite different do Diablo2. D3 you have Best in Slot gear and normally if you want your build to do well you work to get that. Unlike D2 where some gear you'd almost never find, any item of gear is just a matter of time till you find it, either normal drops, gambling etc. In many ways I just don't think it has the same replayability, but the first stage was worth playing.
I recommend do all characters up to maximum, try to see all the places, look in the achievements for things to do, avoid the longest grinds. Set dungeons can give you some unique challenges.