I don't think LLMs are bad because they're not useful. If people didn't think they were useful, ChatGPT alone wouldn't have 900 million weekly users.
I think LLMs are bad because they buy up all the computer parts and leave none for the rest of us to build datacenters that make their communities worse places to live, and consume so much electricity that houses have to be bulldozed to build bigger power lines and/or have clean air act violating natural gas turbines on the property belching toxins into predominantly black neighborhoods, and suck up so much water that there isn't enough for residents, and scrape independent websites until their servers crash and evade every roadblock webmasters put in their way in the hopes of one additional scrap of training material, and buying and destroying rare books because they need training data that isn't polluted by LLM slop like the internet is and cutting the spines off of books lets you scan them faster and more cheaply than if you don't do that, all so that they can produce a machine that generates answers that are wrong 10% of the time, meaning that you have to check them anyway, and code that its authors do not understand and which is extraordinarily difficult to maintain, and make it the expectation to write three bullet points into a chatbot to turn it into a five paragraph email which the person who receives it will then immediately feed back into the same chatbot to turn it into three (slightly different) bullet points. and measurably hinder children's learning. and that's without going into chatbot psychosis and suicides, which we prommy are rare and caused by preexisting conditions.
But they're also useful for generating meal plans or whatever, so all in it's even.