There are active discussions around this, especially in the Securing Critical Projects working group (https://github.com/ossf/wg-securing-critical-projects). These resources will always be scarce relative to the number of open source projects that could benefit, so there's a large focus on developer best practices, improved tooling, and "secure by default" configurations. These are described in the working group README pages (https://github.com/ossf) in more detail.

There are a few ways that OpenSSF and member organizations are already funding direct security work for open source projects, and I'm hoping this expands significantly in the near term.