I find for myself, it depends on a lot of factors, such as climate, coop and run size, whether you free range or not, bedding type, and climate.
I live in the Pac NW so its drizzly and muddy here right now. I use a combo of Sweet PDZ and sand in my coop and I free range every day rain or shine and the girls are free to come and go as they please. I scoop the dropping board everyday or every other day, and spot clean the rest of the coop as needed. I use nest box pads with straw on top and change the straw out every week but change the nest pad once it gets a bit used looking.
As far as cleaning out my entire coop, scrubbing down the walls and floor, and starting over, I've done it twice in 5mos. I feel that for my setup and the daily and weekly maintenance I give it, this is plenty. Basically I do it for the three seasons we have here.