Something I notice seems inconsistent amongst regs is their 3b sizing IP. If MP opens to 3x and you are on the button what size do you 3b to?

I see some regs going as small as 7.5x and some going as large as 10.5x. I used to think 3x>10x was massive then I saw sauce doing it in some of his videos.

What factors should we consider when deciding what size to go to?

thanks