What is the point of an exchange that doesn't let users deposit and withdraw coins? Their only purpose is trading. All assets should be stored in hardware wallets when not being traded.
GameStop won't keep increasing for ten years, like crypto did, without some real world fundamentals.
Even in GME case, you have the short sellers as a backbone for its rise, not just buying and selling for the sake of it. Without the short sellers, GME wouldn't have risen up that much.
Any decent one is using Monero, which isn't necessarily the target of a ton of speculation, I think.
Owning a cryptocurrency means nothing if you can't actually use it as a currency in real world.
Disclosure: my sell orders are always higher than the current market rate