This entire mess could have been avoided if Apple was just upfront about what they were doing. There is nothing wrong with throttling the SoC so that the phone doesn't shut down when a degraded battery can't provide sustained peak voltage.
Apple has been, and still is, the industry leader in providing software updates for older devices. You can install the latest version of iOS on an iPhone 6S, a phone that was released in 2015. The fact that they chose to make this throttling change and keep it a secret was a major whiff on their part and destroyed a fair bit of goodwill they built up from their long support cycle.