Firstly, I’ll address the ‘batterygate’. As Apple rightly states, batteries are a consumeable, and as they wear, performance can be more unpredictable. There was no nefarious plan to slow down phones. There was a decision made, incorrectly or otherwise that the best approach would be to ‘throttle’ the device to maintain stability as the battery aged. Where it all came unstuck was, 1. Apple did not communicate this in advance. 2. Apple did not initially give users the option to turn this function off or on as best suited them. As a result of those errors, all users, impacted or not have had the opportunity to replace their batteries at a substantial discount until the end of this year.
Performance has not, does not, and there is zero evidence to support the assertion that performance degrades with each iteration. Each new release of iOS and Mac OS included new features, new security, etc expected or demanded by consumers. The simple reality of life is that older processors, memory, graphics cards etc may not have the performance to run the new features at optimum speed. The claim of performance degradation is akin to those Win users who wailed about, to use your example, Win Vista degrading their PC’s. The reality was, the new features in Vista overwhelmed the vast majority of hardware more than a year or two old, and even did not support at all a good deal of older hardware/accessories. Truth is Vista was such a dog, it was the perfect example of bloatware. The ‘Performance degradation’ you refer to has been even more noticeable in the Win eco. Win3 to Win 95, 95 to 98… each variant inflicted pain, however while some was due to Ms’s sloppy code much was due to features and expectations outstripping the capabilities of all but the latest hardware.
The current iteration of iOS actually performs faster on any hardware that supports the previous version, so that puts the lie to ‘performance degradation.’ The same applies to Mojave. Granted, if your hardware doesn’t support specific features, those features will not work (Face ID). Mojave runs faster on my late 2012 Mac Mini than El Capitan or Sierra did.
Going back to hardware not supported by Win 10, it has nothing to do with the vast number of accessories available in the Win environment. We are talking equipment from major vendors stuck in the driver compatibility hell with each upgrade (even SP’s in some cases).
Of course, if you want to prevent ‘performance degredation’, ban software innovation and new features. (no move from Scrivener 2 to 3?)