Maybe, but how are they supposed to hire employees to build and run the infrastructure and rent datacenter space / cloud VPSes / etc. if they do it for free?
I'm not being facetious, I'm genuinely curious - hey, the fees seemed high to me, too. Luckily the appreciation of the coins made those icky feelings disappear quickly.
AFAIK, running a full-on brokerage (e.g. Schwab, Robinhood) is probably more expensive as it's highly regulated, with non-trivial compliance costs, for example. Cryptocurrencies are supposed to be new, digital "securities", without the fat of the incumbents. I'm probably oversimplifying this here, but at the age of easy cloud scaling, where their main job is a secure digital wallet storage, their fees are mostly taking advantage of the BTC craze.
To clarify: their % fee isn't that high - the fact that it's uncapped though is pretty outrageous. A $10K trade on Schwab costs a few dollars; on Coinbase, a couple hundred.
I guess once BTC futures are out and one can speculate on BTC in the open market, they'll have to feel the pressure and adjust their pricing.
I'm not being facetious, I'm genuinely curious - hey, the fees seemed high to me, too. Luckily the appreciation of the coins made those icky feelings disappear quickly.