I don't think we actually disagree at all in that fictional positioning should provide the player with an understanding of what is at stake, what their options are, what the costs of those options will be, etc. Also I am not denying that players engage in discussions like "There are obviously mummies in there, we want to use fire and keep out of melee. Wizard, what if you cast a web? That will entangle the mummies and then we can burn them after we pump them full of a few arrows." Right? That I would call tactical thinking. Obviously if the genre is entirely open-ended then this sort of thing devolves more down to inventing cool sounding plot devices, right? This is how supers games work to a large extent. The PCs abilities (at least those of comic book characters) are not really defined in specific detail. So the players invent ways to use them. This is really not too different from spell casters in 5e though, especially at higher levels...
And this is one of those things where I find most versions of D&D come up fairly short. They have super-hero like casters with fairly open-ended spells that might be construed to solve a lot of problems, and fighters, whom you are trying to restrict to basically a slightly fantastical version of what real world people can do (Note how objections were made to the example of the real-life archer, even REAL LIFE is sometimes too fantastic? I find that disheartening).
Given that we are working in a fantasy RPG genre, where anything is 'possible', reality is simply a contrivance. It can have the effect you note, of providing a reference framework for our assumptions of how the world works. However, what REALLY IS happening is the application of fictional positioning and then narration. There will always be some judgment required here, but games will not break down if things are more fantastical. Genre conventions and player expectations should apply, that's all. MOST doors work like the real world, but not all. Travel in the Feywild doesn't work like it does in the real world, etc. Very high level PCs and creatures may behave in very fantastical ways (IE lifting mountains, killing 100 enemies in a single stroke, etc.).