I think that is a pretty silly take on ETFs.
First of all the vast majority of bitcoin will not be held in ETFs.
Some analysts say that most people who wanted to buy spot bitcoin already did it. Those who are interested in buying ETF are only those who wanted to buy but were legally denied the ability to do so, like some pension funds, but how many of them will decide to do it after that one fund lost money on FTX?
So, this is a valid point by you and total fear mongering by Hayes.
And I think it is pretty clear that not enough bitcoin transactions occurring on-chain is not a future worth worrying about. In fact, we have the opposite problem. People already complain about block space being too limited today (just look at any one of the hundreds of complaining threads started this year on tx fees) while Bitcoin adoption is still very early. When Bitcoin adoption is 10x or 20x what it is today, and bitcoin actual usage is 100x or 1000x what it is today, a million or even a few million bitcoin held in ETFs doesn't change anything to alleviate the block space crunch, and its laughable to say it would actually reverse the problem creating the opposite problem.
That's another problem. How many small retail investors who want to buy their first $1k worth of bitcoin will pay 5% of the transaction to move it to a private wallet? Not many, but Hayes doesn't care. He wants you to hold money on his exchange, so fees are in his favor.
Most transactions in the future will be done off-chain on L2s, not because people will just be using bitcoin as a TradFi investment vehicle through ETFs (though obviously there will eventually be trillions of dollars of bitcoin held in ETFs), but because people will be forced off-chain due to transaction costs, which is precisely how Bitcoin was designed.
Hayes is literally worried about the opposite of reality haha, doesn't make any sense.
He's worried that ETFs will beat him in both safety of storing coins with them and transaction fees, which can result in all whales and institutions who used to trade on exchanges moving out and that's going to decrease his revenue.