Wide bore tips on drippers anyways allow you to use the tip for its actual purpose, dripping into the atty without removing the cap, hence the name......
When drip tips first appeared they were sized to fit cartos and premade drippers, the sizes were standardized by the size of the cart threads. You knew a 901 tip would fit a 901 cart 510 would fit 510 etc.
Many manufacturers just stuck to the known sizes so you can change to your preferred tip if wanted.
For those wanting a wide bore, attys like the doge, dark horse, goblin etc have massive tips