this is where you are wrong. difficulty is not something that always rises like that. you should know that difficulty is rising and falling based on the hash rate that comes in and goes out of bitcoin. if more miners come in the hash rate will increase and difficulty will rise and vise versa.
so when do more miners come in? when price goes up and mining bitcoin becomes a lot more profitable. check out the hash rate chart:
the gradient is not the same in these 3 steps that i chose on the chart.
α= first one which is when price is still below $2000 and a lot of fear exists about it crashing down hard back to $700 because of the FUD so there isn't that much increase in the mining power also mining profit increased but not by that much.
β= price goes to $5000 and that ballpark so there is a bigger increase rate of hashrate and difficulty because a lot more miners are now coming in thanks to the increase in mining profit.
γ= is the biggest rate because of the biggest price rise falls in this area which covers going from $5000 to $10k (2x rise) and another 2x rise to $20k
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fi.imgur.com%2FTu1ET5u.jpg&t=665&c=ccIdcOIolkVQhQ)
you see you can not extrapolate the data like this. unless you also extrapolate the price data too like this:
hashrate increased about 14x last year and price increased 22x last year so in 2 years price would be $440,000!!!