i do not agree if bitcoin will only be what it is now, because adoption will make a difference in the function of bitcoin, because when bitcoin is only judged to be the same then that means no change happens, and when that happens then of course bitcoin will collapse, but now is different and bitcoin has a better future with adoption and it will certainly be very useful to be used more broadly
IMO, in the future, bitcoin will be an asset more than an option to make a payment. As the block rewards for miners goes half again, it will have an effect on the transaction fee and it will become more expensive. Once the bitcoin enthusiast notices that, they would just hold their bitcoin and use other option to do payments.