If you want to choose bitcoin over gold, there are a lot of reasons to do that but what kind of a reason is that it will be the next payment system? Gold stopped being a payment system years ago. If you want to compare bitcoin and gold, you should compare it by comparing its qualities as a currency. Qualities like medium of exchange, unit of account, portability, durability, divisibility, fungibility, store of value point out that bitcoin is much more advanced than gold.