Comment by immibis
Don't forget the next part: whenever you point out that Discord requires you to give them your phone number, hundreds of Agent Smiths appear in the replies to say that actually you don't. Who are we to believe - the repliers, or our own lying eyes?
(The Agent Smith effect is something conspiracy theorists made up to explain why every time they show off their conspiracy theory in public, every single person around them suddenly gains the same opinion of them. I'm using it humourously)
The explanation is pretty simple: The most fervent users of discord also have overlap with the longest users of discord, and their account age and usage patterns means that discord's risk systems have never demanded a phone number from them.