To be fair Discord has a lot of monetization potential with Sever Boosts, the premium membership and paid emoji. I'm sure that they could coast and be profitable with those. Maybe adding a couple more paid features over time. Especially if they start charging companies for a better interface to customers via Discord (I'm not even talking about advertising, I mean support and pre-sales communication as well as community management features such as shared accounts so that the support team can talk behind the face of one company account).

Of course this won't happen. Investors will demand more and more profits until the service becomes unbearable and everyone moves off to the new VC-subsidised service.