And that brings up another problem. Even if the price does go way up and the correlation between price/fee value isn't great, but it's still there.
The problem I show in my extrapolation is still very much present.
Regardless of BTC price, higher fees act as a disincentive to make transactions. So any transaction of value around the range of the fee becomes prohibitive (i.e. if you have to pay 5$ to transact, you won't want to transact anything near 5$).
Arguably, that lowers bitcoin's utility as a payment tool, which is the problem I'm focusing on here.
This is why Lightning Network exists. Small transactions will be happening there most of the time, large value transfers will still happen onchain, and in this case network fee won't be a problem, it would be comparable or smaller than what fiat systems are offering.