Mine, while not coming apart visibly will be reported to the dealer next time it goes in for service, it feels just like it has fell apart inside the seat in the same area as you describe, around the wings, ( very loose and wobbly)and mine is the passenger seat and I have only ever had one person sit in it in my ownership and my car only has 11k miles, drivers seat seems fine.
FYI And it squeaks like f**k when they were sat in it😡