The issue was always that of communication and trust.
Communication: at no point has Apple tried to communicate "your phone's battery has gone bad, the device now suffers for it" to the user. Even though they obviously knew that this was what was happening.
Trust: with how openly anti-repair Apple was at the time, how can you trust that this was a honest oversight, and not another malicious action designed to prevent people from repairing their devices?
Apple has improved upon both since. But they're still not anywhere near perfect - and it took a lot of getting their shit kicked in by the media, the public and the regulators for Apple to get even this far.
The issue has always been that people who don’t trust Apple interpret everything that Apple does in the worst possible light.
I make no comment here on whether such suspicion is justified. But let’s imagine that the current behavior (showing the battery warning) had been the original behavior. Then people would no doubt have complained that Apple was trying to pressure people into unnecessary battery replacements.
They now actually sell some parts online, and offer official repair manuals and tools.
That only covers a few basic repair types, the tooling is clunky (for a reason - those tools are designed to allow cheap-and-replaceable official employees to perform basic repairs to an Apple-acceptable quality) and the parts are hilariously overpriced. But it's considerably better than nothing. They also enabled a few repairs that were previously hard blocked by software, and required some incredibly complex hardware workarounds because of it - like FaceID replacement.
Make no mistake - I have zero faith in this being Apple actually trying to be better. It's much more likely that this was them walking back their "no third party repairs never ever" stance under pressure from consumer rights activists and regulators in places like EU. But it's a change for the better either way - and it would be good to see more of that in the future.
Communication: at no point has Apple tried to communicate "your phone's battery has gone bad, the device now suffers for it" to the user. Even though they obviously knew that this was what was happening.
Trust: with how openly anti-repair Apple was at the time, how can you trust that this was a honest oversight, and not another malicious action designed to prevent people from repairing their devices?
Apple has improved upon both since. But they're still not anywhere near perfect - and it took a lot of getting their shit kicked in by the media, the public and the regulators for Apple to get even this far.