All depends on your training goals. if you want to maximize performance on the bike, cooling is worth a few watts. If you want to train your heat tolerance, you might want to go the other way. Also some of us have pretty acidic sweat. Even with a bike bikini and a towel wrapped around my seat post, I still see corrosion of metal parts I sweat on through the year.
FWIW:
https://zwiftinsider.com/how-much-fan/