My question is who do these high fees benefit?
Many persons would easily say miners however when you say so, it seems more like referring to solo miners which in this case aren't the main benefactors. In my opinion mining pools benefit the most during periods of high fees this is because it takes quite a lot of hash power to add transactions to the next block and in comparison, only a few solo miners are able to generate such hash power.
Sometimes higher fees can occur with significant increase in price. The truth is a typical Bitcoin who is not a miner isn't happy about high fees as it can make transactions become extremely uneconomical like the congestion that occured in the last halving block.
In a Bitcoin transaction you have the sender and receiver of Bitcoin. The sender is the party paying the fee and they are definitely not benefiting from the fee. The receiver does not pay the fee nor do they receive the fee so they do not benefit either.
As for this a receiver can also pay fees as a way of spending the coins that haven't be confirmed using a larger fee so that the new transaction gets confirmed faster this is known as CPFP