I remember a few websites having "buy with Bitcoin" buttons circa 2015 but they all seem to have disappeared by now. What can you still you buy with cryptocurrency, except drugs or tickets to crypto conferences?
for physical products… it looks like Newegg still supports Bitcoin. overwhelmingly, the more tech-adjacent the product, the easier it is to find vendors that accept cryptocurrency.
If you invest in gold, you won't be able to even gamble with it. In fact, you won't even have any gold at all. You'll have a certificate from someone claiming that someone else has your gold stashed somewhere.