Today, two common approaches for building embedded Linux solutions are in use.
Many hobby projects start from a distribution like Raspberry Pi OS, and implement the solution in a running system, resulting in a tightly coupled and not reusable implementation.
Commercial development often starts from distribution build toolkits like Yocto or Buildroot. These tools allow to build an optimized solution from source, but do not provide good solutions for keeping the solution secure.
Tools like elbe-rfs allow a third approach. They enable building a custom embedded solution from well maintained binary packages, while separating the solution form the base. This approach helps hobbyists and small teams to develop more optimized, reusable and long term maintainable embedded Linux solutions with limited effort.