Lots of services won’t allow duplicates. For example, you can’t use the same number for account recovery on two different Microsoft accounts. Zoho won’t let you register more than one account with the same number. Etc..

I silo my profiles. I have 4 of them. It’s really hard to do. Everyone encourages you to put all your stuff into a single profile. It’s awful for work life balance and security, but it benefits big tech companies, so that’s why it’s like that.

Do you want separate profiles for your password manager? Pay twice. Do you want separate personal and work windows installs (dual boot)? Pay twice. Etc..