You cannot have individual, singular rules for everything. Everyone leaves out that part: the idea that, if you have a different situation, you necessarily have different rules for each one. That, I completely agree, is not merely unreasonable, it's impossible. No system of individual, singular rules could ever be totally comprehensive.
That's why you abandon the need for every situation to have a singular, individual rules expression. You embrace the fact that rules are always abstractions, and put that abstraction to work for you. My preferred expression of that is what I call "extensible framework" rules. Skill Challenges are one example of this concept. "Montage" sequences are another. What I've heard of Blades in the Dark's rules sounds like another example. DW's moves like Undertake a Perilous Journey, Supply, Carouse, and even basic ones like Discern Realities, Spout Lore, and Defy Danger (probably the single most commonly-used move) are all examples of extensible frameworks: using one core, abstracted structure, you can cover essentially anything within the particular scope of that move. If it makes sense as a journey from one place to another that could be dangerous and uncertain, then that move is pretty much guaranteed to work, or at least be an extremely good starting point with some minor tweaking (e.g. it's perfectly applicable for ocean voyages with light tweaking, but might need some creativity if applied to a vision-quest type "journey into the mind" thing).