My HTC One has gotten dreadfully slower since release from Android releases. I don't think it's exclusive to iPhones - in fact I think android phones are more prone to it.
I guess I'm also lucky to have the latest 6.0.1 on my Nexus 5 running smoothly. Yes, it did get a bit slower after some updates, enough for me to notice it, but considering it shipped with 4.4, I'm still pretty happy with it.
But you're right: it's definitely not exclusive to iPhones. Planned obsolescence, some would argue.
But you're right: it's definitely not exclusive to iPhones. Planned obsolescence, some would argue.