I don't think this would ever go mainstream.
I played
Ingress for a few years. There were location spoofers everywhere.
Niantic could catch them by movement anomalies (move >10m in a second in a wooded area) but if you don't need to keep your game open all the time and just start it after you spoof your location they can't detect that. Crypto investors would not stick around long.
There is network of NFC/ bluetooth location markers, at least in Poland, it's used to find missing luggage etc.
Plus you could think of some kind "Proof of visiting location", so other users have to confirm that