BTC transaction fees in the future really depends on the price of BTC such as denoted in the post at the OP... Imagine BTC at $1b in which 1sats will be equivalent to $1, if the same transaction fees that webare using now is implemented on the then network, it means a transaction fee will be approximately $50k, which is impossible. As the price of BTC increases the transaction fee in SATs reduces so as to tally with the fees on the BTC network.