The problem is supervisors that drop uniques that are just are less profitable than supervisors like zulrah or OSRS gold even vorkath. Even Raids 1 is 3m gp/hr (assuming you see tbows on fall rate, else its 2m kekw) unless you're alting using tbows and 300+ kcers. Tob is 6m/hr+ but only as it's very exclusive (and still relatively new); learning it is somewhat as frustrating/time swallowing as studying inferno with the principal difference being that inferno learning curve is a little steeper.

Most OSRS bosses are like gwd, zulrah and vorkath are only exceptions. I'd love to find these nostalgic hardcore reddit pvmers go 20 hours of bandos 3 guy seeking to make cash for whatever dream equipment update and earn 15m in breaks and call it an enjoyable game when they could have had 60m doing zulrah/vork and proceed to have the time of their lifetime enjoying their gps. My point is this: there should be managers in RuneScape.

It makes the mill rewarding and it motivates players to improve their pvm abilities which is a whole aspect of Buy Runescape gold unto itself.

There's no way to make bosses as rewarding as zulrah or even vorkath without making them exceptionally exclusive like tob (very few folks will take you for initial 10kc and you'll lose 30m+ only learning and constantly wiping with non kc teams before you find a drop), create them fall super strong rares such as the tbow or dex scrolls (which comprise 70% of profit from Cox together), or make them fall supplies.