Sorry for stuff being out of order. On the phone and have no idea how to reorder.
Attribution is a moral right, which is part of copyright. Remove copyright and you remove attribution. Keep attribution and you are preserving some form of copyright.
Trademark is very hard to remove. Not only because of the high economic value it provides, but also because it serves an accountability purpose. Cars, food, medicine, medical equipment, even something as simple as a lightbulb that could turn potentially dangerous if made incorrectly need trademarks to be able to locate the people responsible for it if things go wrong due to failing to comply with regulations. If everybody could bottle their own soda and call it coca cola it would be harder to locate who produced a bad batch. Trademark is a necessary evil.
Conan stories are public domain. Yet while anybody can republish and adapt them, they can't include Conan in the name because the trademarks are still living. Which is the same reason Detective Conan is known as Case Closed in the West by the way.
And with trademarks, the one with the most money has the best chance of establishing one. Right now, little people can and has won trademarks by being there noticeable before, but with a creative work there just isn't enough headstart.