As @lemaitre_dulotus said, that drop scheme isnโt really the problem. People gaming the system is a problem, but the main issue is just the incredible amount of time it takes to farm low-spawn-rate mobs for an item with low drop rate. Itโs a bad design that died some time ago.
The drop scheme is a problem. Maybe not for BBโs in particular but have you looked at drops like
or
Then itโs as hard to get as 1/20000 RNG and 1/4750 RNG respectively. Like your picture says, odds would be horrible.
Still not a DPK problem. (The only DPK-related problem is that counts are reset every ch crash or maintenance, which is another imc iTOS exclusive BS)