Apple recently got fined in Italy for it (though they are still disputing said fine), on an anecdotal basis I always hear from apple users how some new update made their old phone go to shit in terms of instability, software randomly breaking etc, the last update for my Iphone 5 killed Siri. If you were to have an original 2010 Ipad now it still has the processing power for web browsing, youtube etc and jailbroken versions were still running youtube flawlessly until I think last month, but apple had long abandoned it and effectively ensured it became a brick, only jailbroken versions remained somewhat usable.
If you had more open-ended hardware you can always get around these things, the only real limitation being the power under the hood.. With apple products that's quite a difference, they don't want you repairing them and beyond jailbreaking the things you will always run out of working software before the hardware is obsolete.