There’s a difference between hardware and software.
We don’t upgrade to every new device, nor do we ever recommend that. Please read what we write (such as in the article about the new iPhones) more carefully. I’m using a late-2014 27-inch iMac and mid-2012 MacBook Air. Yes, we sometimes buy devices we don’t absolutely need so that we can write about them knowledgeably because that’s the business we’re in, but even now, Tonya is using an iPhone 6s.
We’re talking about software here, specifically iOS 12. It’s a free upgrade, and it works on devices back to the iPhone 5s and the iPad Air, where it improves performance.
On the whole, we don’t write that much about older hardware or operating systems because there’s little new to say. We’re happy to answer questions about such obsolete systems here, but I’m sick and tired of all this negativity about new technologies. If you don’t want to deal with new stuff, that’s your prerogative, but these discussions should remain constructive at all times.
Installed 12 moments ago on my iPhone 7. I made a backup on both of my Macbooks first! It took two attempts. First one failed suggesting update to iTunes which was already the latest version. Several other possible reasons were suggested. None were applicable to the state of my devices or their software. I thought I might need to restore using one of those backups! I followed one of the suggestions provided and restarted my older MacBook Pro (2011) Sierra OS X and tried the update via iTunes again and it worked. If 12 really does correct battery drain issue in 11, I will be pleased.