As a result they also have an 8-year stale (and growing) feature set compared with Linux or FreeBSD. And bringing in used, tested, and maintained code from others brings in their bugfixes as well as their bugs.
If you want the new features, use the systems that have them. OpenBSD would have little point to it if it tried to keep up with the Jones'. It has a unique focus - that's why it's useful to some people.
For example, rather than import the quite huge Intel formulated ACPI stack, they have one of the only non-Intel, non-Windows one out there.
See also their reimplementations or forks of SSH, NTP, SMTP, BGP, etc. all done with a security focused mindset.