I'm sure other people might have different opinions, but the way that I see it is venue really determines a lot. If you lock in a solid venue, that also lets you know what you can do. Does it have room for multiple stages? Is it a one-stage thing? Is it an outdoor venue? Is there camping? Is it indoor? Can you serve alcohol? Things like that can all be locked into place once you have a solid spot to actually throw the show.
Also, beyond paying artists, your venue is probably going to be your biggest cost.
Makes a ton of sense. The festival from when I was younger was hosted once on a neighbor’s farm land, and then the second year at a local fairground. Much more logistically complex the second time around lol