I can see using stable coins as a trading pair to purchase alts on a dex but I don't understand holding stable coins for longer periods of time like weeks, months or years as a store of value; to me this feels way too risky. What am I missing?
There will be absolutely no point on holding stable coins for any period of time. Probably in stead of holding fiats, you may prefer to hold stablecoin but it will be too risky as stablecoins are not regulated ones hence any problem may occur at any time. I am also making use of stablecoins for trading purposes as my local exchange is not having a fiat based trading pair for any cryptocurrency.