Why dependabot tries to update actions from major to major.minor

Dependabot opens PR like this: “chore(deps): bump actions/cache from v2 to v2.1.4” with diff like

-      - uses: actions/cache@v2
+      - uses: actions/cache@v2.1.4

What’s the point in doing this? Isn’t latest (2.1.4) will be used anyway next time my action will runs? Is this should be considered a bug in dependabot?