They’re not all like that.Yeah, I can see that. It's depending on what you mean by "classic," though. A dungeon meant to shave off resources and reward clever exploration - no, I don't think that would work. A dungeon as an encounter flowchart designed to lead the party to a variety of exciting combats and thrilling traps, I think that can work.
It's "D&D5e"(tm) or nothing for these players. And honestly (having read them and played them myself), I don't think they'd be satisfied with any of those other systems.
My idea is something like the following: The party is wrecked on an island and needs to investigate the ruined tower to stop the curse before nightfall. A thieves guild has stolen a McGuffin and the party needs to retrieve it ASAP. The townsfolk have been unable to visit the cemetery since ghouls infested and carved out a network of tunnels - maybe it has something to do with the sarcophagus recently interred in the mausoleum. Who has replaced the prize-winning lager with amber oozes, which are now running amok at the beerfest?
Doom of Daggerdale is an excellent adventure with cool encounters and an interesting mystery.