After update to iOS 14.2 the battery drains 30% faster on iPhone 6S plus, iPad Air2 and iPhone XS Plus.
It is not difficult Apple developers to test specifically for such issues on supported iOS devices, especially not too old ones, before launching updates and to make the update optional for older models until the issue is resolved in a further update.
It's unethical not to do do the due diligence.
appleuserloop
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution