Affiliates and NBC News; they don't want special programming roadblocking the daytime with pre-emptions, and there are places to air it where only Supernatural rerun fans are inconvenienced. Outside the Olympics and golf, the days of gobs of broadcast daytime being sucked up for sports are over, and it's much cheaper to Zoom someone to drone on about today's 'dangerous' TikTok trend than to devote time, crews, resources and money to a sport where only four names win anything (you can bet with Novak's injury NBC knows tomorrow's swan song was going to go out with a whimper).
Also as long as the FCC keeps up this silly charade of brain-dead travel and nature shows with only senior and banned Internet kids appeal being 'educational and informational' the affiliates and networks still have to work around putting that three hours somewhere. Weekend sports with low appeal get in the way.