Does anyone invest in stablecoin? I have never heard although it's possible to get a little profit sometimes. However, people use stablecoin to fix their profit or stop their loss by converting their coin to stable. There's no other use of stablecoin then this.
Im not invest in stablecoin, but i buy stablecoin, like you say, stablecoin for secure profit also stop loss. I buy it also for stategy to making profits.
But if talk about investment, especially long term investment, like OP say "There is no ROI if invest in stablecoin"