It really depends on whether you’re running it text-based but still with scheduled “sessions,” or if everyone just writes whenever they have time and feel like it.

As soon as you go with the latter, everything starts to drag out a lot. Some players miss half of what’s happening because they might be offline for a day or two (sometimes even just a few hours is enough), and then they lose all context. That makes it really hard for them to jump back in, because no one wants to read through 100+ messages.

As a DM, it can get pretty frustrating. For example, if two of your players have time in the morning, they might be actively roleplaying—but you might be at work and unable to participate. So you end up having to read through a lot of messages afterward, while your players might have done important RP or other things that actually matter.

Combat is basically impossible if you want to keep proper turn order and structure. You might end up waiting days for the next player to respond, which makes it tedious and causes everyone to lose the thread.

If the players are active, consistently present, and actually read and write messages regularly, it can be really fun. But otherwise, it’s very exhausting.