The simplest explanation of bitcoin’s “use case” right now in developed countries

Bitcoin allows people to take a weak form of money that loses purchasing power over time and convert it into a strong form of money that can’t be debased. So the “use case” is simply this: buy bitcoin using dollars that you do not absolutely need (in a lump sum or a little bit over time), do nothing, and in 4-5+ years, your purchasing power increases. If you want to sell your bitcoin for dollars because you want to buy something, then you can do that very easily.

If you absolutely need dollars to pay bills every month then bitcoin is probably not for you right now. But if you have any surplus of dollars after paying your bills, and if you have patience, then buying and holding bitcoin is the best way to increase your purchasing power over time.