I don't understand this actually lost at conscpicuous leisure. The point of status games is to signal power that could destroy a potential opponent.

If you think status signalling reduces to a threat of force, you are missing out on the most important parts. Cooperative signalling and in-group/out-group signaling are extremely important.

Wearing a heavy gold necklace does it (it could pay for hit men).

Gold chains are a lousy symbol as they are easy to fake and actually pretty cheap by first world signalling standards. Hence they are currently only used by underclass people or those not long removed from the underclass.

What am I missing? Why didn't all those conspicuous leisure guys (or later contrarians or authentics) just walk around with gold jewelry for example?

In the past, leisure demonstrated ownership of capital (i.e. I don't have to constantly be working because my money makes money.) Leisure activities can also demonstrate social group membership (going to a yacht regatta vs. going to an avant-garde fashion show.)