That's not true. Might be at Mesa with your OT rules, but not at Envoy.

Envoy has by far the best OT rules of any regional, perhaps any airline. Every single thing you pick up is added on top of your guarantee at premium. Crew scheduling can not hide trips or withhold them for reserves, and we can take flying from reserve assignments and get paid premium for them.
This has a reverse effect on how you think OT effects staffing. We are effectively flying at 150%, whereas if the company was adequately staffed, they would not be paying the premium to fly these trips.
So, the more our pilots pick up, the more it incentivizes the company to bring back pilots so there would not be so much open time left.
OT pickups cost the company more than bringing back the furloughed pilots.

A blanket "never pick up OT when pilots have been furloughed" might not always apply.