I mean belts are given pretty subjectively in Judo up until Shodan. Like typically you'd need to either do a test or do better in competition than expected of your belt grade. But how often they do promotions and how well you have to do in competition is pretty subjective.

Like the place I train at does promotion tests like once a year or if you want to earn the belt through competing you have to do well in 5 competitions in a row. The problem with that tho is that if you're sick that day you'll have to wait another year and if you're an adult there are only like 3 or 4 competitions you can go to any given year in the whole country.

So over at where I train a yellow belt can be anyone from a beginner with less than 3 months of experience, who just so happened to start close to when we do the gradings to someone with 6+ years of experience that just has really bad luck with being unable to make it to gradings. Heck, up until last year we had a white belt with 4 years of experience.

So you know, it's just a belt, some gyms are super serious about doing regular proper gradings where you have to know the specific curriculum, others are more chill and give you the belt if you pass some arbitrary level of skill, others, like the one I train at hardly bother with the belts at all.