Li Shenron
Legend
The only straightforward offensive options available to everyone in combat are Attack, Grapple, Shove and (from DMG) Disarm.So, that's the problem then, exactly as I stated: a lack of meaningful options.
You can get creative with the environment or equipment and try to find ways to restrain, entangle, slow, blind, trip, or distract your opponents (or even set them on fire) but these aren't codified in the rules, presumably because having fixed rules might have accidentally made one option too convenient at the detriment of all others (even Disarm was hidden in the DMG just in case), while leaving them rules-free means they are environment-dependent and thus more controllable by the DM, but it doesn't mean they don't exist. But leave called shots alone, as they are like opening a can of worms.
Beyond these, there are feats and class features behind a paywall.