Bitcoin is best for long term savings, but that is not the problem that stable coins solve.  If you get paid every 2 weeks, but need to buy groceries, for example, more often than that stable coins could be a literal life saver.  Imagine: you just got paid and know that you will need to buy food again in a week, because you don't have refrigeration.  Bitcoin could be up or down 30% in a week.  Your local currency will for sure be down 20% in a week because of hyperinflation.  Your government regularly steals the money in dollar denominated bank accounts, if they're even allowed to exist.  USD stable coins will probably preserve practically all of your value over such a short time frame.  In the long run USD will go to 0 and Bitcoin will be the only money, but you don't care about the long run, you just care about being able to eat next week.  This is an important and valuable use case in a small but growing number of countries. 

 If you don’t have refrigeration, you should buy a fridge first not a Stablecoin 😆