Yes. But they do care about landfill:
https://www.fairphone.com/2016/07/14/closing-the-loop-the-garbage-collectors-of-the-mobile-industry/

Is there any other smartphone producer, which is doing that too?


yes, lets start from Apple

http://www.apple.com/recycling/

Actually, every electronic device imported in EU will be recycled. Manufacturers (or importers) pay some fee at the time they put device on market and in theory there is some on other side of cycle who is responsible for collecting and recycling. Companies doing recycling are not only paid by this money but also there is money to be made from raw materials.

In third world countries there might be a problem but as I said garbage is not garbage but opportunity to make some money so as long as there is system organized it will be done. Certain % of devices can not be recycled.