One thing I noticed, which always felt possibly-illegal, was how Binance and other exchanges would frequently freeze up funds that didn't meet minimum withdraws. If a coin fell to too-low of a price, they'd essentially just keep them. Sure, it is only $5-100 here and there, but that all adds up. Where does it go?

With a real bank or exchange, I'd expect some ability to sweep up my accounts and get a paper check for 50 cents if needed.