It is 7 days across flat Iowa
It isn't all flat. Look up the "Driftless Area" of Wisconsin, Iowa, and Minnesota.
Also, so what? From what I can tell one of the goals of this event is to be approachable to people who aren't hardcore cyclists.
If it was across a State not so boring, I would consider
Well, convince an entity in state you deem less boring that they should sponsor a bike ride across their state.
I'm not an Ultracyclist, but seriously even for a 65 year old man (me) that is not difficult
Good. Bicycling is a great way to stay in shape. We all have what we're comfortable riding. I personally don't expect the distance to be an issue for me, the longest day I'm riding will be below 75mi, which I haven't done in a day yet, but I think I can and I'm training to be more comfortable with it. I expect my challenges to be the Iowa July heat, the hills when I get to the Driftless, and riding hard on consecutive days.
Try this - RAAM -
https://www.raamrace.org/
This is across all of USA, winners usually in 9-10 days! 3,100 miles about
So, RAGBRAI is an acronym for the Register's Annual Grand Bike Ride Across Iowa. Bike Ride. Not Bike Race. If racing is your thing, that's pretty cool. I wish I could do races and be remotely competitive. But I don't see that happening. From what I've heard from people I know who have participated, and various YouTube videos of people participating in RAGBRAI, it's more of a weeklong party on bikes.
Maybe it's more like a tame, moving Sturgis for bicyclists. Sure, I personally think Sturgis and the Black Hills are fun to explore, but I bet a lot of motorcyclists go just to hang out with friends, drink beer, and stay in town.