Torchlight, and really all diablo-likes, has the problem of being too simple/easy, with higher difficulties primarily item-gated more than whatever skill/strategy; its long term value comes from multiplayer + grinding/trading qualities of random drops, and less so from well, playing it as-is.
As a result, they've never really satisfied my roguelike itch tbh.
Also, if that multiplayer + grind/trade/build characters + sets is the main value you get from Torchlight, then probably consider path of exile, which pretty much optimizes purely on the multiplayer aspects of Diablo 2 (Torchlight lacks some purpose imo; they set out to do a better Diablo 2, but didn't really pick a place to optimize, and didn't do well enough at optimizing everything, and didn't really remove any fundamental flaws)
I agree with your description. Torchlight II was a compromise - The original idea was to play Divinity Original Sins but I pushed us towards a simpler (and less expensive) game because I suspect neither of us would be able to devote enough mental effort and/or sustain interest for a long time.
If my suspect is wrong, we will try to move on to something more complex.
As a result, they've never really satisfied my roguelike itch tbh.
Also, if that multiplayer + grind/trade/build characters + sets is the main value you get from Torchlight, then probably consider path of exile, which pretty much optimizes purely on the multiplayer aspects of Diablo 2 (Torchlight lacks some purpose imo; they set out to do a better Diablo 2, but didn't really pick a place to optimize, and didn't do well enough at optimizing everything, and didn't really remove any fundamental flaws)