My sprout bearing is already bad. Grinding need advice on new bearings

[Splizacular (Thomas)]

A question on Bearings

Hi all, I have a quick question. Bearings! When one buys a new throw online from, it doesn’t matter but let’s say a new “Japan technology” or a new “offset”. Where does these different manufacturers get their bearings?! I mean do they all make their own or do they buy ones online and put them in their various models they sell so we’re unaware. May seem a weird question but I’m drying to know. Thanks In advance.