Holding the money in the bitcoin will be the far better option as compared to the money holding in the USD.The USD value will not increases with a time period and only few dollars we get as the interest which is 4-6 percentage.But if you hold the money in the bitcoin,it will give you 10-20 percentage based on the time period you are holding in terms of bitcoin.When the market was moved in the positive way,you can convert the bitcoin to USD.This will give good profit by the bitcoin trading for the certain period of time.
bitcoin is undeniable a good profitable investment but I guess in this case, OP seemed to want instrument to save his wealth without any volatility which fiat actually serves that purpose despite still having fluctuations.
therefore if we are talking about whats better in this case, I guess having USD in bank might win because these bank even if there goes bankrupt still gonna get back up by the government therefore ensuring that we won't lose any money at all.
different with stablecoin that is owned by private company in which could go bankrupt anytime, therefore in this case saving USD in bank is far better.
though stablecoin like USDT i don't see its gonna be bankrupt anytime soon.