>>1
You have two hard problems:
1. Userbase
2. Moderation
And these are, of course, intertwined.
So in an ironic fashion, whatever gathering place you make is orthogonal to what you're seeking: varied contributions.
Making the place is only step one in a stairwell of plush that'll sink and suffocate if you aren't careful.
textboard.org keeps a modicum of variety due to it being one of the few active textboards I know that keeps absolutely any activity at all and leans toward longer contributions.
Most textboards I've seen elsewhere consist of low-effort shitposting, which gets boring.
But again, the distinction isn't about whether there's activity, but if the activity is amusing enough to fuel a tab-open.
In most ways, textboard.org is fragile in how it entertains.
And if you face hard facts, there isn't much more to be said here, or done, other than vague contributions from stilted engagements -- solo stories making a mild side-arc, if you could call it that.
So, the best question you ought to ask yourself is, what type of content/interests do you want your new textboard to hold?
And when you select that, you must ask how you plan to recruit detailed anonymous contributions that you most likely enjoy.
Sustained anonymous activity usually leads to nowhere; most would like to imagine it being otherwise with all of the 4chan arcs making a supposed dent in the real world. But for niche boards, those dents are revealed to be exceptions, and all you can expect are graveyards with the occasional spirit whispering how Code Indentation is forced and what to configure your Emacs installation with.