Can someone explain the whole voter fraud thing to me

I honestly don't understand the side that says there is voter fraud at all

How were they statistically impossible? Isnt votes getting added how voting works? And if the system is broken, doesn't that also mean 2016 is illegitimate too?

https://discord.com/channels/707691030748594288/724106950018596964/794243335178551296
Isnt this happening in a capitalist system or is this just satire cuz im confused