I don’t necessarily agree with this. Just because software is open doesn’t mean it’s actually getting audited and it also doesn’t mean the people doing any auditing know what to look for.
On the other hand, closed source (or open source) software can be audited by reputable companies just the same.
The fact that it’s open, in my opinion, can give people a false sense of security with the software.
The log4shell vulnerability existed in the code since 2013 and wasn’t found until the end of 2021.