ChatGPT was a research prototype thrown at end users as a "product".

It is not a carefully designed product; ask yourself "What is it FOR?".

But the identification of reliable sources isn't as easy as you may think, either. A chat-based interaction really makes most sense if you can rely on every answer, otherwise the user is misled and user and conversation may go in a wrong direction. The previous search paradigm ("ten snippets + links") did not project the confidence that turns out is not grounded in truth that the chat paradigm does.