Like I said above, I guess it depends on how we are defining "actionable". To me...receiving the narration from the DM allows me to choose one of several actions-- attack again thinking the enemy is almost dead and I can kill it; not attacking if I think the monster isn't close to dead and I can't risk putting myself into jeopardy; attack but not kill the enemy in order to take it prisoner and then interrogate it, thinking that the DM might decide to maintain the narrative fiction they have established if my roleplaying during it takes advantage of the gaping wound (by healing it, sticking my hand in it and causing pain etc.) Those are all actions I can take.
Now are all these actions all narratively-related, rather than mechanical in nature? Yes. But that's fine by me! As I've said I really don't care that much about the mechanics. If I'm DMing, I do not need, nor require the players to have mechanical rules in place to do whatever they want. If I describe that the orc had a gaping wound and was bleeding badly and the players decide they want to not kill it and instead interrogate... and they make all the narrative choices like I mentioned above-- one playing "good cop" by healing the orc so as to not kill it, the other playing "bad cop" and using the wound as a torture method (or anything else they can think of)... I absolutely will play into that narrative and adjust any mechanics I end up putting into the scene by giving Advantage, Disadvantage, moving the orc's morale up or down etc. etc. based on their narrative actions they took in response to my narrative offer of the gaping wound (and then of course any extra info that comes out of the inevitable die roll.)
To me... the narrative is improv. And like in proper improv, it's always more effective to the scene to "Yes, And..." Drive the scene forward by "Anding..." whatever offer a player made via their narrative, just like they "Anded" my narrative offers. And none of that requires the D&D game mechanics. What the mechanics DO do... is to give us ideas as we improvise our actionable narratives to make new or different narrative choices we might not ordinarily have made on our own had the scene been completely improvised without any mechanics at all.
If the player and myself were improvising this fight... every single fight could be the player saying "I chop off his head and he dies." Which is perfectly acceptable and actionable as an offer, and then I as the DM would then take actions off of that offer. But the problem we could run into is that an improvisor can go to that well too often, and thus over time it no longer makes for interesting drama. Every improvised fight starts and ends with a single offered line of narrative? Possible and acceptable... but perhaps eventually not that much fun. So by adding game mechanics into the mix... now the player usually just can't declare "I cut off its head", but instead we will need to play out the scene bit by bit and use the results of the mechanics to have interesting things happen, and thus compel us to make new and perhaps more interesting dramatic actions and stories via the narrative that we might not otherwise have made. The mechanics lead our improvisation the same way playing an improv game like "Film & Theater Styles" will lead the improvised scene in a direction that it otherwise wouldn't go had the rules of that improv game not been in the mix.
But again... this is particular to my games and my tables and I freely acknowledge that probably few other tables think of or run their D&D in this way, so I don't expect many others here on the boards to necessarily agree (or at least not go as far as I tend to think of it.) And that's cool. But it does explain my personal beliefs of why I don't think game mechanics are the end-all-and-be-all of Dungeons & Dragons, and why getting so hung up on them (in every sense) removes the part of the game that I think is the most interesting.
