This is a misconception. The "lag a lot" is very much debatable. For a lot of areas, specifically OpenBSD, is pushing the boundaries[1], not lagging behind. That's why they don't guarantee user space stability or even ABI stability inside the kernel, to move faster. Just check this recent case[2] about Linux is not enforcing IBT/BTI on its binaries and this being a known problem since 2001, while OpenBSD is solving this.

But again, people have different conceptions of lagging behind. Some people think not having a graphical installer is to "lag behind", when this is pretty much a design decision and not a problem of fewer people working on new things.

[1] https://www.openbsd.org/innovations.html [2] https://undeadly.org/cgi?action=article;sid=20230714121907