Perhaps (though, my experience refutes that) durability is an issue for a single surface material, but not for a properly applied composite. My Baby Super Clown is wrinkle free after a couple of years. Try the technique on a junker, let it age, then criticise! If you ain't tried it, you have no valid standing. Others have used the technique, as noted, and say it is durable.
I really get anoyed at those who post "well I don't really know, but......"
Incidentally, iron on films are NOT a shrink film, but a stretch-on material! Applied correctly they look tight before you ever touch them with a heat gun. Get Faye Stilley's books and learn how to do it right. I did a Monokote demo for our club. One wing was pre-covered and a member was very impressed. I said "I haven't shrunk it yet!" That's how the job should look if you want it right!
Learn how to do it right before saying it is no good.