Everything is over inflated at the moment so it's a dammed if you do dammed if you don't kind of situation. However, a global ETF is going to return the highest yield for minimised risk, and even if the world markets crash. You're still holding something of value.
Everything is jacked up. This one is a full send for better or worse. I don't think there is a good way to diversify that way - short of maybe crypto if you're a believer