It's not on purpose, it's a lack of IT coordination and has been a long-standing issue in the government. As an example, until about 2010-2012, nearly every US military base hosted its own email server and employees (military, civilian, contractor) received an email address like first.last@base.af.mil (replace af with another branch as appropriate). Now it'll be first.last@us.af.mil.
They consolidated each branch's email and other comm systems over a number of years with good and bad results. Cross-branch communication could still be improved, but it's much better than it used to be. Cross department and agency communication is still broken. And the only purpose is so they can retain control of their fiefdoms.
It's not on purpose, it's a lack of IT coordination and has been a long-standing issue in the government. As an example, until about 2010-2012, nearly every US military base hosted its own email server and employees (military, civilian, contractor) received an email address like first.last@base.af.mil (replace af with another branch as appropriate). Now it'll be first.last@us.af.mil.
They consolidated each branch's email and other comm systems over a number of years with good and bad results. Cross-branch communication could still be improved, but it's much better than it used to be. Cross department and agency communication is still broken. And the only purpose is so they can retain control of their fiefdoms.