Bitcoin long investment doesn't requires buying at low price in order to sell at high price, one can buy even at the peak price so far the intention is to buy and hold for longer period of time, prioritizing buying at low price to sell at high price can be more of trading strategy but when it comes to Bitcoin long term investment one can buy at anytime the money is readily available for investment irrespective of the price point , what is most important is achieving a good size of Bitcoin up to a reasonable amount which will put you in good profits.
If you are long term investor , you can always buy bitcoin without waiting for it to dip more especially if you are using DCA method to accumulate bitcoin ,your target should be to get a reasonable amount of it in your portfolio. But it is wrong to think that all investment in bitcoin is because the investor want to make good profit at the end .people can invest in bitcoin in a way to retain value. Just imagine you have $3000 at your disposal and you want to retain this money for a longer time. You can invest it in am asset that won't lose value. So it is wrong to think that all investment is aim at making good profit
You are suggesting that some people invest in bitcoin as a hedge against inflation and not necessarily because of the profits. Even if this may be true, the number of people who put their money in bitcoin as a hedge will be very insignificant. It is possible perhaps some people might take advantage of the fact that inflation in fiat is high whereas bitcoin might present some form of remedy, the primary motivation for every investor in bitcoin is to have their investment grow beyond the amount of money they invested. This is why there is generally some form of excitement among bitcoin investors when price is rising.
I have three purposes for investing in bitcoin and they are: to profit from the investment in the future, as a hedge against inflation because fiat is doom to die with time as we have seen in my country over the past few years, and finally to save my money for the future probably my retirement because I cannot think of any better place to keep my money in. If I had a way of pulling my compulsory pension funds to bitcoin, I would have done that but it is not possible because it is government policy that such funds can only be touched after retirement from active service.
My only consolation is that I am investing part of my salary in bitcoin using monthly DCA method. That way I can still realize something significant before my retirement which is still very long from now.