The numbers are self reported by hamas anyway, so the real number is likely even lower than that.

Not sure how lemmy implements this, but I suppose it’s not a trivial task in such decentralized environment. Imagine 10 users from instance A subscribed to instance B and then instance A went permanently down. If B holds number of subscription requests it’s now out of date. If B has to poll every instance it’s federated with it’s additional arguably unnecessary load. So yeah local subscriptions are a low hanging fruit