GoodBlock recently published an article on Understanding Telos REX.
"Telos REX receives funds from users renting the use of resources just like on any other EOSIO chain — but it also receives an additional 1 million TLOS each month from the TEDP. [...] The current annual percentage rate yield for Telos REX is over 30%. Remarkably, this high yield is not earned at the expense of inflation."
Read more: https://medium.com/@goodblock_info/telos-users-guide-understanding-telos-rex-d94d081cd7bb