Full details on the differences that can be found in this Diablo 2 Resurrected vs Old comparison of the multiple options from a visual or tech analysis angle.
A new reign of power begins with the arrival of the Warlock. Wield forbidden magic with its Chaos, Eldritch, and Demon disciplines, and test your might through updated Terror Zones and new endgame challenges. Discover even more updates throughout Sanctuary with new Unique items, Runewords, and quality of life updates that’ll make your descent all the more rewarding.

Diablo 2: Resurrected rolls out a fresh update, bringing a host of gameplay improvements, bug fixes, and the launch of Ladder Season 8.
Blizzard should release physical versions with offline play. I'd buy copies for my PS5 and Switch to go with my original Battle Chest.

Diablo IV may be the latest entry from the Diablo series, but it can sure learn a thing or two from the iconic Diablo II. Both of these games are different and similar to each other, but Diablo II's phenomenal presence should still be more appearing in Diablo IV to make the game even better in its current state.
Diablo 2 Re farted
Maybe I need glasses but the original version looks better to me and has more details like bricks on the road.