[Emmanuel Micah]

Because to NAT, effective address usage strategies, and its vast existing infrastructure, IPv4 has endured for a long time. Nevertheless, it is unsustainable due to its tired and constrained address space, which complicates NAT, and its inability to effectively serve the increasing number of devices. These problems are resolved by IPv6’s enhanced functionality and wider address space.

[Emmanuel Micah]

Exactly.

But then with the increasing number of users, it will be exhausted if an an alternative like IPV6 is not introduced.