they finally bowed mid last year https://www.nerdwallet.com/article/travel/southwest-google-f...

Your point is completely valid, but... Southwest now has an arrangement with Google Flights to allow their listings there.

> Amazon listings are blocked from google shopping

I see Amazon results there all the time. 3 of the visible 8 sponsored results are Amazon, in the non-sponsored results an Amazon listing is either first or second in every category.