I've never been able to make published adventures make the sort of sense I need them to make in my head, for me to feel comfortable running them. Literally everything I've run in 5e has been homebrewed, including the setting. I literally do not think I could run a long published adventure. At this point, my prep for a campaign is a few hours--working out information about where I'm starting things, writing up what I'll give the players about it, figuring out what might be relevant and interesting for the characters the players have made up (based on what they've given me in the way of backstory, and based on what they've told me about when I've asked them questions about their characters' experiences in/of the setting). Oh, the joys of a persistent setting. My prep for most sessions involves a good deal of background processing, then like fifteen or thirty minutes writing up some ideas, then letting things play out for a few sessions. My prep load is not onerous.I've been running adventure path adventures since 3.5. Prep is not something I particularly enjoy. Heck, I run modules far, far more often than I run entirely self made adventures. I might fold, spindle or maul the adventure and change stuff, but, actually self-author an entire campaign? Thinking about it, I don't think I've ever done that.