Absolutely, as soon as they hit that mark where things get really specialized, they start failing a lot. They do generalizations on well documented areas pretty good. I only use it for getting a second opinion as it can search through a lot of documents quickly and find me alternative means.
They have broad knowledge, a lot of it, and they work fast. That should be a useful combination-
And indeed it is. Essentially every time I buy something these days, I use Deep Research (Gemini 2.5) to first make a shortlist of options. It’s great at that, and often it also points out issues I wouldn’t have thought about.
Leave the final decisions to a super slow / smart intelligence (a human), by all means, but for people who claim that LLMs are useless I can only conclude that they haven’t tried very hard.