Specifically with Ethereum, you can automate margin-calls and auto liquidation. This is the basis for a lot of DeFi, which recently was the blockchain topic du joure. The idea is that you can trade in options, or margin loans, with the smart contract ensuring the seller of the option is sufficiently collateralized. This removes brokers and exchanges from the equation, which should make things easier.

Notably, FTX also offered the option of margin loans and options, though they were centralized. This turned out to be bad, not because it made things more difficult, but because they stole all the collateral.

Also note that the DeFi approach would likely have failed here, because the smart-contracts that determine the value of the collateral do a simple "units owned * current market price" computation. That doesn't account for price slippage. In practice the markets are quite illiquid, so selling some collateral will drop the price of that collateral quite quickly. DeFi currently has very little holistic risk management. When you have a lot of, say FTT, as collateral from counter-parties, that leaves you quite vulnerable. If FTT drops quickly, many people will get margin-calls. If they all default, then you get left with their FTT. If you try to sell that, it will crash the price even more.