Is tough, I was thinking there are numerous styles of yo-yoing, and then there’s humidity style.
In other words, the tricks you can pull off (without gloves) that don’t turn into a mess due to sticky hands.

Humidity can make a tough trick even harder, wonder if competitors change their routines outdoors when they know humidity could be a factor, i.e. omit a trick.

Add humidity and wind, and it’s quite a handicap. A bit adverse to gloves, can’t pinpoint it, maybe it looks too serious about the whole thing, but they might really help.

Then there’s talcum powder, but do I really carry it around? not

I went to a contest a few years back and it was held outdoors in the middle of July. It was extremely humid out and everyone was sweating. I remember my shirt was sticking to me I was sweating so much. That, plus contest nerves were making my hands sweat like crazy. At the time, I was a naive yoyoer so I didn’t own gloves or anyting of that matter. Granted, you can imagine how my routine went.

What I did learn was when yoyoing in humidity, there are some basic essentials you need: 1) use brand new string before you go on stage, 2) use gloves on bot hands 3) if you dont want to use gloves, I saw other players using baby powder or deodorant on their hands to ease the moisture.