Be careful. They compare reserve oz. Not grade. Throughput is higher, grade is lower which sounds better to say -15% oz reconciliation than at least -25% grade recon.
Throughput covers some sins but those tonnes still carry a processing cost nominally 50% of overall costs.
Also spacing too wide is the go to for any resource that doesn't perform. The issue normally is not the drill density but poor critique of the model. Resources are almost put out to the highest bidder these days rather than trying to reflect what is mineable it's all about funding under the illusion of "robust economics"