Bitcoin as a store of wealth

Could someone explain to me how Bitcoin could ever be a store of wealth given that although there are only 21 million Bitcoins you can and will have 21 million Bitcoin like coins that do exactly the same thing and generational change will ensure that they do get produced and gather adoption as the years go on. The young people on the planet today buy Taylor Swift records not Elvis so what's going to make future generations stay loyal to Satoshi and not relegate him to the status of Elvis today who is still the king but with very little sales and relevance.