We want to see how high Bitcoin can reach for the last decade but let's just give an example of how much Bitcoin was a decade ago, so 2015 started the year with $200-$300 price and now look how much it is just in a decade.
Considering 2015 for speculating about 2035 makes sense but the price level seems misleading to me; otherwise I guess you need to consider the ATH by 2015. Because, bitcoin is known for dumping up to ~80% in a bearish year which means we may get into a complete different price range if we consider the prices at random dates.
I only mentioned about the price during the start of 2015 and yes, we should also consider ATH done by 2015. Its volatility really is something else and could reach the ceiling unstoppably but when it dumps a lot, it will be as low as it can be.
although the multiplier should only get around 4.5x - 5x, might be not that much but with the expensive pricing, it will take time.
By considering the 2021's ATH was just 3x from the previous ATH, I guess smaller multiplier will be more realistic. At the same time, bitcoin's fundamentals are suggesting about logarithmic appreciations of price level against constantly shrinking supply given that new adaption rate variable. So, I guess 500k is not a big thing for a decade of time.
We will have two more cycles within a decade so, if we say that 3x down to 1.5x or within the range of that for those two cycles in a decade, it's very likely that we'll see a $500k per Bitcoin.