Fresh just doesn't work well enough compared to recirculated for me. If the car isn't getting cold enough, recirculation being off is always the culprit.
I've questioned why fresh is even there (seems unlikely co2 would be the reason) - it's always going to be less efficient and you can open a window if you want fresh air.
Anecdotally I feel fine driving for 2 hours straight in recirculated air with closed windows.
Fresh is there at least partly because cars didn't used to have AC. If you are driving in-town or stop-and-go having a fan on your face with fresh air takes a bit of the edge off.
Also in heating mode, there's little reason not to use fresh, as we can heat up cars really easily.
I've questioned why fresh is even there (seems unlikely co2 would be the reason) - it's always going to be less efficient and you can open a window if you want fresh air.
Anecdotally I feel fine driving for 2 hours straight in recirculated air with closed windows.