I'm setting up my second dungeon for crawling. I'm learning something: Its so easy.
Prepping for 5e is a process. I don't create a location, I create encounters. And those encounters can occur randomly and in weird places spatially, and each encounter is like a mini story with an inciting action, rising tension and dramatic climax.
I'm not doing anything like that in my dungeon. I just place a bunch of shit around that would be funny if it killed the players, and that's it. I can focus on crafting the location into something that's good. And its so fast. If I wasn't using a VTT, I could probably prep this dungeon in an hour before gametime. Including dice rolled encounter tables.

In fact I spent so long prepping TSR modules as well. The ones written by Gygax are all very complicated, even the so-called easy ones like B2, T1 or G1.

It's so freeing to just let go of the story and plot and sandbox and everything, and just be like "This corridor goes down 120 feet..."