I'd wager that 95% of humans wouldn't be able to do 10x10 multiplication without errors, even if we paid them $100 to get it right. There's a reason we had to invent lots of machines to help us.
It would be an interesting social studies paper to try and recreate some "LLMs can't think" papers with humans.
The reason was efficiency, not that we couldn't do it. If a machine can do it then we don't need expensive humans to do it, so human time can be used more effectively.
With enough effort and time we can arrive at a perfect solution to those problems without a computer.
This is not a hypothetical, it was like that for at least hundreds of years.
But then you're not measuring the ability to perform the calculations, but the ability to invent the methods that make the calculation possible.