It's a good idea to save in bitcoin but then bitcoin is volatile in short term so the risk is quiet high in short term but if considering long term then bitcoin is best choice Viz vice with fiat fiat is best option for short term because it's leads volatile in short term so saving in fiat for just a little amount of time is good.
When it comes to longterm savings it is advisable to use store of value such as bitcoin. Some people are so relaxed in saving money with their countries currency, savings is good but I think will be waste to save money in the bank for longterm because doing this won't be profitable in any way.
Saving in bitcoon is a better financial decision for anyone because it will surely bring value in the future, saving in bitcoin is the only way to escape economic inflation.