They also suck if you want to find something that's almost exactly like a very common thing, but different in some key aspect.

For example, I wanted to find some texts on solving a partial differential equation numerically using 6th-order or higher finite differences, as I wanted to know how to handle boundry conditions (interior is simple enough).

Searching only turned up the usual low-order methods that I already knew.

Asking some LLMs I got some decent answer and could proceed.

Back in the day you could force the search engines to restrict their search scope, but they all seem so eager to return results at all cost these days, making them useless in niche topics.