I don't know. My broker does not allow me to trade US warrants so I have not much info.

I agree with what someone said earlier though, if you have a margin account, you can probably manage to exercise your warrants as if they were cashless anyway (something to see directly with your broker).

Now about the question on "why don't we all just buy warrants?" I would say that right now, if you believe in the company, it is possibly a better investment (this is NOT an advice of any kind! Everyone must invest according to its own risk appetite and after doing its own DD). But in general, warrants are also more risky as they can be more volatile and as the deadline gets closer, you risk losing all your investment if you cannot exercise them (if the pps is below the strike price + what you paid for the warrant) and if no one wants to buy them.