With extremely high heat porcelain coated steel developeds crackes due to differential expansion .
That's why a weber kettle has about a 10 year life span !!
Aluminum may warp / ? Melt at extreme temps of charcoal grilling.
I've never heard of a PK cooker body failing!
I make charcoal fences & baskets out of aluminum expanded metal , coals touch the walls , can't tell any wear & tear on any.
If I'm betting the PK body will long outlive you without any special care