Yes, there are limits in Active Directory. From maximum number of objects to maximum number of GPOs applied, Active Directory has its restrictions. Here are a few of them:
A domain controller can create “a little bit less” than 2.15 billion objects during its lifetime
Users, groups, and computer accounts (security principals) can be members of a maximum of approximately 1,015 groups
You can apply a limit of 999 Group Policy Objects (GPOs) to a user account or a computer account
You should avoid performing more than 5,000 operations per LDAP transaction when writing scripts or applications for an LDAP transaction
It cannot support anything that is within the realm of Azure AD