Speaking as a Quest 2 owner, most games on there feel overpriced. Combine that with how Meta treats older hardware and you can safely guess that many players are probably not feeling confident buying games on that storefront anymore.
Meta recently made developers not allow new updates or installs for older headsets which effectively locks games you paid for away from you being able to play them unless you buy a newer Meta headset.
Conversely, you buy it on Steam where the prices don’t seem to be nearly as much in some cases too, and you can use it with nearly any PC VR headset and they don’t limit it only to newer headsets. Games I buy on Steam feel like mine and I actually have long term access to them. The Meta store’s versions feel like a long term rental situation, as long as I keep buying the newer headsets which is not feasible.
The only benefits of buying on the Meta store is that it can be taken on the go and doesn’t require a PC to play.