Waterproof gloves: do they exist?
Nope, they all have a hole in where your arm goes.
AND, the surface area of skin means a lot of sweat.
Add in lots of taping/glueing and the area available to breathe is minuscule.
AND you are resting on water, so forcing it in under large hydrostatic pressure.
AND that taping and gluing is flexing lots, so fails earlier than elsewhere.
Yes you can pay a FORTUNE for properly waterproof gloves, however it is only a matter of time before they fail IME, or one wrong sleeve 'setting' and the water pours in.
Personally, I have a few pairs, and expect to swap them through a ride and hang em up to dry at the end.