Most big companies still have travel agencies/companies manage their corporate travel. I can’t remember who we used when I was at Amazon, but I made a similar complaint to my manager once given I could fly cheaper in a higher class on a different airline (also one I had heaps of points with so I would have preferred it because I’d be able to upgrade further and/or use the lounge).

Turns out the price I saw in the booking portal isn’t actually what Amazon paid. It’s kinda more like a rack rate listing. But then there’s all kinds of discounting/cash back that happens on the backend based on the amount of travel booked each month.