I'm wondering if good old Samsung or Verizon pushed software to it to make it slower so that we upgrade to the next big thing...
What are your thoughts?
Since we're on the topic of paranoia, I'll share mine.
With my last two Android phones, each one has worked fantastically out of the box, but as time wore on, they got slower and slower. My first phone (Droid 2) was rooted, so I got RDS Lite and flashed it back to the original Froyo state. It flew again, but by the time I'd downloaded all the OTA updates, it was back to crawling, and this was without any apps installed. My Razr M was the same way, slower with each OTA update. (On my D2, I eventually went with Liberty ROM, and that got me another 2 years out of the phone because that ROM was so freaking fast).
So to explain this performance decline, I have a theory. It may be complete nonsense, and I probably have no idea what I'm talking about, but it sounds good, so here it is.
When you buy a new phone, it's optimized for the ROM it comes with. Samsung may even do some tweaks on that ROM to get the best possible performance out of it, because they know those new phones get tested against each other and are heavily scrutinized. Also, the hardware on your phone is usually the latest and greatest when it's brand new, so that ROM will be expecting that hardware.
Now you've gotten an OTA update. A new version of Android, and when that happens you've lost those tweaks. Samsung doesn't care how fast your phone is anymore because you already own it, and the next big thing is out, so there are none of those tweaks on the new ROM. So right out of the box you take a performance hit. Also, since your phone was released, newer, faster hardware has hit the market, so the new version of Android might be designed to take advantage of that. After a few years and a few major OTA updates, you now have an old phone with a new ROM. Think about trying to run Lollipop on my old single core D2. It probably won't be fast if it even boots at all.
The same thing probably happens with apps (especially games) but not everyone loads phones up with apps, and not all apps (especially non-game ones) need speedy hardware.
This theory is why I've decided to freeze all OTA updates. It's more of a test than anything, but I REALLY like my phone the way it is, and I don't see any reason to have Lollipop.