> What makes the problem intractable? We can now do both voice recognition and synthesis at human levels, and any video game programmer from the 1980s can keep some objects from running into each other.

Great point!

It must be that despite the reliability, obvious advantages, and accessibility to "any video game programmer from the 1980s", everyone else is just choosing not to do it.

Alternatively, these things are not as simple or as reliable as you, a person who has no familiarity with the problem, assumes them to be.

I guess we'll never know ¯\_(ツ)_/¯