Because A records don&#x27;t mean complete control over domains.<p>There is a difference between &quot;I can serve content under this domain (currently)&quot; and &quot;I control this domain (and can decide where it points)&quot;.<p>DNS domain validation is the right way to do domain validation. But it&#x27;s slightly harder for users, which is why HTTP(s)- or E-Mail-based validation is being done more often.