The only reason that the fees can be so high is if the network utility is valued high enough to support such use.  So you can't simultaneously say bitcoin will become irrelevant AND the fees will be high.  You would be, again, refuting your own argument. It COULD be true though that many users that use bitcoin for cheap transactions today, would use other currencies (or 2nd layers solutions) for such transactions in the future.  But this doesn't speak to the value of the system, because, and like I quoted Szabo and Finney explaining, bitcoin would be very valuable as a high powered settlement layer, and then for that function the higher fees would be completely acceptable.

The higher fees come from transactions that are sending large value.  You can't claim that the system will be irrelevant when bigger and more wealth players are using it. Its just not a system for the average citizen and it was never meant to be. 

But it is still being adopted because its value is increasing in relation to domestic fiat, which is exactly what fuels adoption, not transaction capacity, and not the cheapness to transact otherwise litecoin etc. would have a billion+ dollar market cap.