Movement skills and displacement skills predicated DOS2. Mobility is king, especially with the way Larian builds combat zones that often start with enemies far away and/or on higher terrain.
DOS2 has skills like Teleportation and Netherswap vital. And most people had access to at least one other from a skill tree, e.g. Tactical Retreat, Phoenix Dive, Cloak and Dagger. The ability to quickly close distances or transport yourself instantly is critical in winning Larian combat objectives.
Pretty much. Even Tactician difficulty in DOS2 becomes extremely trivial when you give your entire party access to teleport and nether swap, and 1-2 mobility skills. At that point, the only thing that has a chance of wiping your party are bosses that can do enough damage to one-round a party member, if not your entire party at once. Which happen to be the majority of late game fights.