From all the major flaws presented in Bitcoin one could say PoW is the major flaw of them all making the coin more centralized than even most people can't afford to keep up with other miners, these are day traders doing there thing again making profits on your losses, beware most say it's like gold it doesn't need to be fast but in reality it just isn't so secure.
I think you are always concluding on Bitcoinprice based on what happened 2017, the pump that happened sudden there was too fast and that is why it crashed since it didnt slowly get to the price.
Bitcoin adoption is still at its early stage and still has a very long way to go, within the next 10 years, at least, over 500 million people are expected to have gotten a glimpse of the system and start making use of it for their financial operations, some will come to trade, some will use it to make payment and majority of people will keep it value like gold, and as these people come in to perform one or 2 transaction frequently, we will keep experiencing gradual growth in the price of BTC till it reaches ATH but for now, its stability is what we need to achieve this and if it will stay on $4000 for now to achieve that, it wont be a bad idea.