I didn't have time to read through 7 pages of comments, so this may well have been already said, but I'm calling BS. I have a 4½-year-old iPhone 13 Pro; I replaced the battery (for free with AppleCare+) after 3 years once it got below 80% (and then promptly canceled AppleCare+). My plan is to make it last 6 years when the new rumored 20th anniversary iPhone is due out. It didn't run Apple Intelligence when iOS 18 came out, and it won't run Siri AI when iOS 27 comes out... yet it was allowed to update to both of those versions of iOS. I still get the new UI updates and some new features and changes, but get that the more advanced updates require more powerful hardware. I also have an old first-generation Apple TV 4K (I've been patiently waiting for the long-rumored new model). It runs tvOS 26, even though it's not powerful enough for Liquid Glass and most of the advanced new features, it was allowed to update.
So why couldn't they take the same approach with watchOS 27? Let me have a consistent UI across my other devices, and have a footnote for Siri AI requiring a Series 9/Ultra 2 or newer? Similar to my iPhone, I replaced the battery on my Series 8 when it turned 3 this past December (they replaced the whole watch with a refurbished one for free, and then I canceled my AppleCare+ on it), and I planned on making it last 3 more years until a hypothetical Series 14. It does what I need it to, the battery lasts all day, and I'm not playing this planned obsolescence game... it looks like I'll miss out on watchOS 27 and 28 until I upgrade, and hopefully the hardware update will be a meaningful one by then, too.