Eli5: Why monarchs have numbers in their names to keep them distinct, why can’t they have a different name?

Question

like why king xyz 2 and not some other name
?

In: 72

Answer 1

It’s not just a monarch thing, everyday people do it too.

If my name Gorgle. My son could be Gorgle Jr., his son Gorgle the 3rd, his son Gorgle the 4th. etc.

I’ve known several 3rds etc and even a 5th or two in my life. It’s not suuuper common, but it’s totally a thing (at least in English/Western culture).

Why not just name the Glorgiete, in lieu of more Gorgles? It’s just a respect and familiar memory sort of tradition.