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".