that was my case as well with the fold 2. I upgraded to the fold 5 since launch last year and can say the toughness on the main screen between the fold 2 and 5 is night and day. not a single scratch or bubble anywhere on the folding screen, held up very well.
I have a friend with the fold 3, and the main screen is basically destroyed, much like your partner.
it has to do with the way they are folded. the fold 5 uses a “tear drop” fold similar to the Motorola phones.