Regarding the doctor's signature thing, that seems a bit preemptive to say a single flawed study invalidates the entire field and tech, especially when the tech is working as intended in that case and it is user error in the study.
And of course, like any tool it should be utilized thoughtfully. Any form of technology directly takes away from the skill previously utilized to get results. Flint and steel took away from the rubbing sticks together skill. The combustion engine took away from many different professional skills.
Consider that, in this case, we don't just have to replace diagnosis but could augment it instead. What if every hospital around the world could augment regular medical care with a single machine processing results. Every single check-up could include a quick cancer screening. If the machine flags you as 'at risk', a doctor could then see you for human diagnosis and validation. The skill of diagnosis is still needed and utilized, but now everyone can have regular screening instead of overwhelming an already overtaxed healthcare system.
Again, all I'm saying is that there are practical, useful use-cases for the technology, they're just not what we are doing with them.
Edit: as an after thought, I'm no expert here. As far as I understood, LLMs are a type ML, but ML encompasses a way broader category of 'AI'. I'm mostly against LLMs for just general use like they are currently. I am advocating for ML as a whole, with thoughtful application.