I’d rather have access to the full level of performance and then replace my battery as needed. A win for me in both performance and longevity. Apple’s approach has hidden the need too discretely and conveniently for my taste.
There’s already a “Low Power Mode” toggle. Why couldn’t throttling be rolled into this existing option for those concerned about power management (it probably is). So why the further hidden, negative option management? Why not provide an alert that tells the user their battery needs replacing? My phone already auto downloads unwanted updates and nags me to install them. Deleting only repeats the cycle.