"It's clear that Tether was the kickstarter to the mania by printing about 2 billion in 2017 on a total market of 1 - 10 billion in the last 10 years."
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3195066
99% of the flow in to the other stable coins comes from Tether.
If you make up 2 Billion and then sell those 2 billion for 2 billion TrueUSD, all you do is change names around.