Yes. Decarb if you are going to eat it.
Let's say you make brownies with cannabutter using the simmering water method. My boxed brownies bake at 350° for 28 minutes. It takes approximately 30 minutes at approximately 240° to decarb. Although your brownies reach 350°, how long are they at least 240°? You dig?
If you make cannacaps, you don't have to decarb. But if you want to get high, you have to decarb. Whatever your medicinal vs. recreational views are, some folks will eat raw dope for raw dope medicinal virtues while others prefer to medicate recreationally.
However you make your dope edible, it needs to be dried. Decarbing or drying raw weed with heat makes for a bad dope product.
I have recently found shatter for making brownies, but any sort of sugarless sauce or badder will work. It saves hours of work and mess, and you can dose it pretty accurately. Since that route probably isn't in your purview, my next harvest will be dry rub kief'd. A portion of the kief will be decarbed and added to a batch of brownies. Using kief still saves hours of work and mess, but you can't dose it without testing.