Yep. Washing your technical apparel 1-3 times a year will help maintain its water resistance and breathability, as oils and general grime will reduce the effectiveness of the DWR (the outer fabric won't make water "bead up" as well), it can create a way for moisture to get through the waterproof membrane, and it'll clog up the membrane, making it less breathable.
Every piece of apparel has a limited life and you'll want to replace it eventually, but cleaning it fairly regularly can extend that lifetime.
This article is worth a read for more info.