No? LinkedIn lost a lawsuit about prohibiting third parties tools from accessing its site, Matrix has strong interop, Elite Dangerous offers OAuth API for sign-in and player data download, and so on. There are others but that’s sixty seconds worth of thinking about it.
Mastodon metastasized the user store but each site is still a tiny centralized user store. That’s how user stores work. Doesn’t mean they’re automatically monopolistic.
Discord’s taking the Reddit-Apollo approach to forcing them offline — half-assed conversations for months followed by an abrupt fuck-you moment with little recourse — which given Discord’s free of charge growth mechanism, means that — just like Reddit — they’re likely going to shutdown anything by that’s providing a valuable service to a significant fraction of their users, either to Sherlock and charge money for it, or simply to terminate what they view as an obstruction.
So my small app that had maybe 50k users at peak never allowed third party integrations. How is that not a monopoly by this definition? Would it have been more or less of a monopoly if I had allowed third party integrations?
The DMA has language defining thresholds below which it doesn’t apply. At 50k users, I would not expect or call for the DMA to apply. Discord has slightly more than that and I would expect the DMA to apply to them, assuming the EU found them to be an in-scope platform. Given their recent introduction of gaming and such inside their ‘we’re not just a chat server anymore’ feature expansion, one could argue that they’re now voluntarily opting in to platform regulations that wouldn’t have applied if they’d just stayed focused on messaging.
For consumer products the DMA focuses on companies with at least 45m monthly active users in the EU. They also exempted some categories that might otherwise qualify e.g. the DMA doesn't appear to cover video gaming consoles because they are "special purpose hardware".