What are the advantages of 7x7 ArUco markers compared to 4x4

Question

I've been using ArUco markers for a while now but I've only ever used the 4x4 markers / dictionaries and I'm just wondering what are the advantages of using say 5x5,6x6 or 7x7?

I would have assumed that the markers with bigger matrices would be able to represent more numbers but it seems that no matter the size the max number is 1000 markers?

Is the only purpose so that you could have 2000 markers if you used both say 4x4 and 5x5 libraries for example?

I've tried googling this but I can't find anything which answers my question.