KDP accounts are linked to your Amazon accounts.
So, yes you may have two are more KDP accounts.
BUT – and that’s a big BUT, the problem comes when you link to your Tax ID or other unique IDs specific to you (PAN number, SSN number) where your details from the first account may match to your second account when Amazon runs a background check or even when simply validating your new account.
If you have two separate bank accounts, two separate Tax IDs, then separate KDP account may not be a problem – by two – I mean yours and your spouse’s or any other family member’s whom you can use with their permission.
To conclude, there is no real reason why anybody needs more than one KDP account unless your first account is in trouble and you want to jump to another KDP account that you need to have as a backup. If the publishing is done correctly without getting into copyrights or plagiarism issues, then one KDP account is enough.