It is really annoying when you have a fly line that is "new" and it is delaminating.
I have a DI5 fly line, that is 4 to 5 years old and has been fished about 4 times.
So it is not new, and in years it is not new as well, but on Sunday, I gave it to a fly fishing companion to use, as he left his at home.
When we started it looked like brand new, but after about 3 hours the first signs started showing.
Another hour later, about 10 spots where the core was showing thru.

Then I have a DI3 from Airflo that is probably 16 years old, and sees plenty of fishing every year and only now starts showing wear and tear.
There is no better subsurface lines than those of Airflo.