Climbers take their shoes off to reduce the pressure on their feet. This helps them reduce pain and prolong their session.
Climbing shoes are usually very tight, and, after wearing them for a while and climbing a few routes, they can get pretty painful. Taking them off in between routes allows the climber to reduce that pain and pressure from the feet.
This is more common in climbers who downsize their shoes, which means that they take a few sizes smaller than their actual street shoe size.
Because leaving them on in between routes can end up being painful, shortening your climbing session, and making every attempt on the route more and more painful and less efficient.
Taking your shoes off in between routes lets your feet rest a little bit.
Because we are in pain! But not that much pain. Generally, climbing shoes are not comfortable, and leaving them on for a long period of time just starts to hurt after a while. Taking them off in between some of the climbs just lets our feet relax a little bit, and delays the session-ending feet pain.
