It really depends on the band and shopper connectivity. For 2.4Ghz the Wi-Fi six/6E sequence is generally all 2x2 and only supports MU-MIMO in a single course (send only).
My speculation is the fact outside 6 GHz https://allyourbookmarks.com/story18125381/the-5-second-trick-for-best-wifi-7-access-point