Diablo 2 can be beaten on any class without grinding at all, just organically clearing areas to progress further. Normal and Nightmare don't require any grinding, especially if you picked one of the many powerclasses (pretty much every elemental build is ridiculously strong all the way until Hell Act 1). Hell is a true test of skill, patience or ability to find or make items. D2 has many ways to craft and create new equipment for yourself. It's just that most people associate D2 with late-game items that take months to complete and whose market has been pretty much taken over by bots.
All I can say is there's a world of difference between a veteran who understands the limits of his class and can make it work with self-found gear and someone who does thousands of MF runs and twinks out his future characters based on what he finds. Nothing wrong with either playstyle, but nevertheless, Diablo is quite capable of providing different challenges and thrills. The point of D2 is that you always set the "end-game" by yourself. Some people were happy with just beating Baal once, others wanted to see how far they can take a gimmicky build, some others want to earn mad d2jsp money, some just want to have every unique item in the game, some want to PvP, some want to reach the Guardian title (for beating Hell on Hardcore), etc.
Even Ubers can be done with a budget character if you instead rely on skill and prep.
D1 wasn't particularly grindy either if you just wanted to get to the end.