I'm struggling with this question these days, actually. And I don't really know what I want.
Back in the olden days we'd have long and intricate campaigns, made up of multiple shorter adventures, that would run its course in less than a year. But we were young and carefree and game-obsessed. We would sometimes game for days at a time.
Today, noone has that kinda time, and if I had it, that's not how I would choose to spend it. But a part of me longs for those epic, convoluted messes of campaigns from back when. Last year we finished a just-short-of 5 year long campaign, but with one 4 hour session every two weeks (and it's share of cancelled sessions) and while that was a fun campaign, where I was in part able to recapture some of that "long epic run" of yesteryear, in RL time 5 years was too damn long. It hit a couple of lulls over its run, which hit much harder in the slower, more intermitten, style of play.
We took a hiatus after that as I started working on a follow-up, but I realized I was creating a way too overloaded mess of a thing, crammed to the brim with all the ideas and concepts that I wanted to play with that didn't fit into my last campaign, and it would immediately crash under its own weight.
So I scrapped it and went back to basics. Strong opening adventure (I hope), with a few different options for follow-ups and just see where it goes. Maybe it will be long campaign, maybe it will be a series of one-shots. We'll see. That campaign was supposed to start earlier this year, but alas, the world decided to go down in flames instead.
So yeah. I'm trying to find some middle ground here, I want to run a campaign that's satisfying for me and long enough for everyone to develop their characters, but not something that's half a decade long.