Why are you guys using stablecoins?

I guess this is one of these "I never understood it and at this point I'm too afraid to ask" questions, but fuck it, I'll ask anyway.

I completely understand investing in any crypto that isn't a stablecoin, but I just don't understand the point of using stablecoins over cash. They are worth the same as cash, they don't save you anything in terms of taxes or make your tax declaration easier, they are not more practical to store than cash, etc.

It seems that the only advantage of stablecoins is that they give you crazy interest, but this comes at the cost of accepting the risk that your stablecoin may suffer the same fate as UST? Which is normal, you don't get interest without risk.

Is this really the only reason why people use stablecoins? The interest they get?