If by "compost bags" you mean those paper bags used to collect yard waste (they are not just for leaves) they are fine to use as part of a mulch system. When I collected bagged yard waste I would go back to the places I picked up from and offer to return the bags still in good condition to be reused and most often the people would prefer to go to the store and spend more money on new bags instead of recycling the old ones so I used them in my planting beds.

I have used them before. Cardboard is a little easier to get laid down just right, but the bags work fine.

Kimmq's story reminds me of going to the store where you have 1 item and they start putting it in a bag before you can say you don't need one. So they are handing it to you by the time you say it, so they pull the item out of the bag and throw the bag in the trash. Ay yi yi. <eyeroll>

That annoys the hell out of me, and I often think it's on purpose.

There are some people who actually hate recycling and even a few who think it's a government plot to control everyone. "I can waste all I want as long as I pay for it, don't take away mah freedums!" Some of us are short on the concept of 'civic duty'.