In my view, what this ultimately is is a free Discord client. The server is there because I assume the developer liked Discord’s API and wanted to be able to self host a server using it, but I imagine the majority of users will be interested in using this client with discord.com.

Keep in mind that “don’t use proprietary platform, switch to x/y/z” doesn’t account for the unfortunate reality that people may have contacts on that platform and switching wholesale and cutting off contact with those people is an unreasonable tradeoff. While a completely free service would be ideal, using a free client with a non-free service is still an improvement.