"All software has bugs" is the most meaningless statement ever. It is just used for bonding with fellow bug writers who sit at a virtual campfire and muse about inevitabilities.
Demonstrably some software has fewer bugs, and its authors are often hated, especially if they are a lone author like Bernstein. Because it must not happen!
Projects with useless churn and many bug reports are more popular because only activity matters, not quality.
"All software has bugs" so "be wary of the one trying to say they haven't had any in 3 years" not so "I guess all are equal". For extremely low security bug rates either the scope is extremely narrow, the claim is dubious, or the project is a massive effort which the community talks about directly in posts rather than plugs (e.g. curl).