I don't get what the OP means . The name stable coin says that they are stable with some form of Fiat mostly USD . So you are not getting anything by investing in stable coins.
lol, your post got me cracking
, i guess the op is not fully aware about the nature of stable coins or he must misinterpret what he meant, whatever the case maybe, it has been said already, stable coins are not for investment rather they are mostly for preserving what you have, i think op needs to go back and do some more reading or we need to do some more reading. 
I was stunned when I read that post. I was just skimming through to see what the comments were. You hit it right on the head.
I think stable coins are an ok place to place a minor amount of money. It helps the general ecosystem. But unless you're getting a good return - it's not an investment.