In the past, we can choose to use Microsoft account (Hotmail/Outlook) to setup the login or use an offline account (like how we did traditionally) during the installation.
Recently, the "offline account" option isn't available any more if Internet connection is available during the installation.
There are some advantages to use online account, but if you still prefer offline account, there are 2 ways.
First, cut off the Internet during the Windows 10/11 installation.
Second, cheat them while maintain the Internet connection.
Microsoft will continue to ask for a valid Microsoft account if you provide an invalid Hotmail/Outlook account. So, simply enter "sample@hotmail.com" and fill in with any random password, till the system gives up.
Then the offline account option will be available.