My very spirited LO started climbing out of the crib just after his second birthday. We tried transitioning him to a big bed and it was a disaster. We ordered a crib tent, but they weren't locally available and in the time it took to ship we realized that the root of the problem was that his sleep need had dropped, he wasn't tired enough to nap, and, being spirited climbing out of the crib at nap time was the next logical step, lol.
We started waking him earlier in the morning to increase his day time sleep drive, he went back to napping and seemed to forget that he could climb out of his crib as he never really did it again, so we ended up returning the crib tent. Ended up being in the crib until he was 3.5 yo. I felt comfortable leaving him in the crib even though I knew there was the potential for him to climb out because he was big and agile and had done it repeatedly without hurting himself.
Hope things improve soon!