Often marketing platforms (like Hubspot or whatever) lets you create multiple landing pages which might all be on a subdomain(s) to rather than handing full control of the root domain to the platform. In these cases, you wouldn't want pages.ctvnews.com to appear as the display domain.
Also not to mention the myriad of services and ways that act as a middleman for the click, in the same way that the link display on Twitter appears as ctvnews.com but it's actually a t.co link