Do Magnaflow's wear out?

I've had these

MAGNAFLOW 3.5 X 7IN. OVAL STRAIGHT-THROUGH PERFORMANCE EXHAUST MUFFLER 11132​

on my car for about 6 years with around 35,000 -40,000 miles on them. I've noticed this summer that they seem louder especially when taking off. Wondering if there's baffles in there that eventually wear out? I love the sound going down the road, just seems a noisier when taking off.