My plants definitely have good, fresh media since i repot every 6 months to a year depending on the species. Also the media is almost always quite nice looking when i do repot. Sometimes the media in the pots of the water loving phrags is broken down but that's it.
Why are you repotting so often? It seems excessive.
to be honest, I don't really know! I enjoy repotting so maybe that's why? The plants don't seem to mind and bloom faithfully every year or more though.