But that also means that the price will eventually flat-line, *some time* over the next couple decades. I mean it can't keep growing in price constantly, forever like this. Moore's law itself has already flat-lined (despite chip manufacturers not wanting to admit it).
The log of the price as a function of time (log in the y-axis and linear in the x-axis) is not going to look like a straight line but a convex curve (bending downwards). This indicates BTC is slowing down with time when looked over linear time because as the log-log graph reveals what scales up linearly with the log of price is the log of time, so scales. In other words, every time BTC scales up by a factor of 10 we need an equivalent scaling of time so 10 days, 100 days, 1000 days, and so on. This looks like a slowing down in our linear understanding of time or diminishing returns. It is ok because even if this means the 1000x returns in a few years are behind us, it shows the system is stable and robust. Power laws are typical of robust and nonfragile systems. To answer your comments there is no real ceiling also because it represents the price of BTC in dollars and the dollar is inflationary and can go easily to zero relative to BTC. Inflation is already part of the model given we had considerable inflation in the last 15 years. I expect the system to continue similarly for a few more decades but we will see.