Unless businesses are paying for server boosts[0] (which would only be useful for 1080p60 screen-share or a 50mb upload limit), there's no way to use Discord for business or pay extra for business use outside of creating a free server like any other; there's no real reason to choose Discord for business either, since it has no real retention policy (other than storing messages forever, for now), DLP is non-existent, there's no SSO/SAML, etc. The only reason to use Discord for business is if you really like Discord and/or other parts of your business are on Discord, like if you run a video game.
There are "businesses" that have communities, and want to own/manage them. Discord works much better than Slack as a platform for "official" managed open-membership communities; it's seemingly a use-case the Discord staff have put a lot of thought into.
Think: every content-creator or streamer.
But also: regular corporations that provide platform services that people build their own stuff on top of, such that people want to talk to each-other about the service rather than just talking to the corporation about the service. (The sort of thing you used to stand up a hosted forum for.)
Yep, I agree about limited industry but it does work in that respect. I see it used a lot for content creators as a way to organize and tier out their fans as well.
0: https://support.discord.com/hc/en-us/articles/360028038352-S...