I split time between Florida and North Carolina. Riding in the heat and humidity in Florida, I find that a base layer for me just gets overwhelmed with sweat ands makes me less comfortable.

In NC riding in the mountains where it can be hot climbing and cold at altitude and descending, a good base layer that can wick moisture is and advantage.

So for me I use a base layer where the temperature and effort is going to vary with the altitude and terrain, and where the heat and humidity is not enough to just overwhelm the base layer’s moisture management capability.