Real Reason Last OS Update Makes Your Device Slow

[STLVNUB]

O.P.

We All Know That What Usually Happens Is 
The Last Supported OS Update Slows Things Down A Tab
Some Think That It's Apple Forcing Users To Buy New Gear, Half Truth

My Thoughts On This Are:-
System CAN'T Manage The Extra Workload That UPDATING Dose!

Let's Face It, The Updates Get Bigger And Bigger, 
So The Resources Need To Handle The Extra Workload Are More Intense.
e.g Need For Faster CPU, More Ram, Faster HDD/SSD Etc

What Are YOUR Thoughts On The Subject