Personally I find interesting the general idea that adding constraints to a system leads to creative outlets, forcing the participants to break entablished thinking patterns. The fun stuff here is not the content, but the alternative paths the writer has to take to convey the message.

For one, it's a gimmick that brings attention to Mastodon, which as a foss/decentralized alternative to Twitter, is interesting in its own.

Second, it's based on a centuries old literature/poetic challenge/game, of writing a text based on some constraint, and especially with avoiding a specific letter (a "lipogram").

Third, the challenge itself, which removes the ability to use the most common letter in English, is amusing enough to people. It makes you think harder about phrasing, and solve how you express something in alternative and creative ways. So it's a kind of fun game, like e.g. Scrabble.

Fourth, besides the fun/challenge factor, exploring alternative ways of writing a sentence is something that most people seldom think hard about, but that has applications in general writing too (in other words: what you gain by working around some constrain can make you a better writer in general, even when there are no artificial constrains imposed).

P.S. How are things going in Vulcan?

Thinking about constraints in art is intriguing, but for my part I simply find it a lot of fun. But possibly it's just not your bag and that's OK.

It makes you discover new words. Enriches your language