I regularly check geopolitical markets to see if a breaking news story is substantial or not, and find it useful. It can help distinguish between propaganda and intelligence there.

It does seem like there could be a distinction between markets which require genuinely knowledge and analysis (geopolitics), versus pure gambling (sports, crypto up/down 5 minutes, etc), but I'm not sure who's going to bother making it.

(Geopolitical) prediction markets almost always tend to overreact. This is expected from retail, so I'm not sure about the signal.