Since this presupposes Markdown of the flavor that comes with YAML frontmatter, and that frontmatter is doing all of the heavy lifting, this is more like a YAML database than a "Markdown database".
In any case, nowhere is it indicated why this approach (no matter what you call it) should be preferred over e.g. recfiles.
In any case, nowhere is it indicated why this approach (no matter what you call it) should be preferred over e.g. recfiles.