Says whom? And define 'living'? At very low levels even living things appear to be machinery[1].

[1] https://www.ted.com/talks/david_bolinsky_animates_a_cell?lan...

Considering what we've accomplished in the last 100 years I think it's easy to say that within a billion years we could develop the technology to simulate and create life. The question is would it take a billion years or a million or only 10k? You can't say it's impossible. It's just a matter of when.

It depends on how you define life.