There is a cost to owning your own wallet. It can easily be $200 for a cold wallet. I only have $360 in my total Eth costs. The cold wallet still had trading costs. There are other advantages of Coinbase. If my NFTs make a lot of money, Coinbase has a $30/month program with no transaction costs. I am not signed up for that currently since I am not selling my NFTs currently. Also Coinbase is very secure and insures assets.
Also the “innovation” was for the libertarians. I am not of any belief in libertarian dreams.