If you want to use Discord nowadays you need a valid phone number, that's it.
Either you agree with it and use their service, or you don't and delete your account with all your data.
They use this to battle spam accounts (with quite some success, been over a year since I've been contacted by scammers), there is no good way around it.
You massacred my boy there. It doesn't say that at all. Amdahl's law is actually a formula how much speedup you can get by using more cores. Which boils down to: How many parts of your program can't be run in parallel? You can throw a billion cores at something, if you have a step in your algorithm that can't run in parallel.. that's going to be the part everything waits on.
Or copied: