Dunno if it counts as a failed campaign, but I was running an adventure in a Basic D&D game wherein the goal was to find an Apparatus of Kwalish. I decided fairly quickly that the module itself was not ideal for accomplishing this goal and just told the group at the start of the next session that they'd searched that temple top to bottom and found only a journal entry that led them to an ancient temple in the middle of nowhere (which conveniently was the site of the adventure I'd decided to run instead).
Then we decided as a group to take a side trek and play a a bit of Dungeon Crawl Classics, and that's been so enjoyable/popular that we've found little enthusiasm for resuming the search for the Apparatus.
Sorry if this is off-topic but I'm curious what's been more appealing to your group about DCC compared to Basic D&D? Is it a system/mechanical thing or something else?