It's simple. It's because AI is the scariest technology ever made. Human intelligence has proven itself capable of doing a lot of scary things. And AI research is keen on building ever more capable and more scalable intelligence. By now, the list of advantages humans still have over machines is both finite and rapidly diminishing. If that doesn't make you uneasy, you're in denial.
AI, the way you are describing it, has not been invented yet. It is a fiction. What is called "AI" today is an extremely vague marketing term being applied to various software technologies which are only dangerous because humans are dangerous. Nuclear & chemical weapons are also "very scary" but only because the humans who might decide to use them in fits of insanity are scary. I'm not in the slightest bit uneasy abo…
Even LLMs of today routinely do the kind of tasks that would have "required human intelligence" a few years prior. The gap between "what humans can do" and "what frontier AIs can do" is shrinking every month.
What makes you think that what remains of that gap can't be closed in a series of incremental upgrades? Just 4 years have passed since the first ChatGPT. There are a lot of incremental upgrades left in "any of our lifetimes".