I shoot almost every weekend with one weekend a month being 2 matches back to back. I try to clean it after and or before every match, so that I start each match with a clean gun. On the back to back matches it almost never gets cleaned as I'm to lazy to clean it that night after a whole day at the range. As a bare minimum I always oil up the slide if I haven't had a chance to clean it.
I'm sure a well made gun can run hundreds of rounds without cleaning no problem, but why not give yourself the best chance of your gun operating at 100%?