There is zero chance that the target users for Discord is going to try anything more complicated than Discord, so basically all the entries in this list. I recoil in horror thinking about me explaining Matrix even to the most tech savvy friends I use Discord with and I really really hope people would stop recommending it.
The target user group for Discord actually is children and teens. Look at that UI and how it‘s trying to sell you „swag“. Then, Discord is not uncomplicated. From „Servers“ not being servers, multiple account onboarding levels, to what happens when Discord believes you are a bot or are using a blacklisted IP.
I believe you underestimate the average age.