I will say I've also been in discussions regarding the efficacy of forms where someone will say the techniques of the forms were useful, because in sparring they did a down block and punch combination.
Which also holds true that I feel this connects well from technique to form to sparring when you are looking at the basics, but as you get more advanced the art tends to diverge.
So my thoughts on what patterns are actually for (from a TKD perspective) I think diverges from the mainstream. I look at them (in some ways) as a dictionary. You could read a dictionary cover to cover, and learn very little about how to apply each word in correct context or conversation... but that doesn't make a dictionary worthless.
I have never subscribed to the idea that patterns are a pretend fight. On their own, patterns do not help you learn to fight... they help you fine tune specific skills that can be applied to a fight.
A stance is a freeze frame of a moment in time. In application, you would never lock into a position, holding an arm out, then transition to another static pose. We do this, to hardwire specific movement pathways and ranges of motion into the subconscious. Are there other ways to accomplish this? Of course... but this is one way.
Anyone who says that a horse stance would never happen in a fight is just wrong, or has never taken a single BJJ class.
Every BJJ student learns to 'Stand Up In Base'. Now freeze for a moment at the point when you just finished taking your rear hand off the ground. Where are you? You are standing in a horse stance, bladed to your opponent, with your lead arm outstretched toward them. Of course, you don't just freeze there, but for a moment, that is your position.
So why stand there longer than 1/4 of a second? Maybe just to develop your quad muscles... and there are other potential benefits I could get into.
The largest benefits of patterns is in building muscle control, balance, and power generation through the movements between the poses.
The individual end poses could be set up 1 by 1 and a picture taken, and it could look perfect. It is how the body moves from 1 to the next that holds the actual lessons. In my style of TKD (like most Karate styles from what I understand) power is meant to be generated through waist/hip rotation horizontally. Maintaining balance while stepping to an exact position, while generating maximum power without sacrificing control, is the lesson of our forms.
The benefits do not show up like 'I learned how to jump to a Left X-Stance while striking with a downward backfist, so now I do that in sparring'. It's, 'I learned how to generate power in a strike while mid air, maintaining my balance and posture so that I could transition to a more stable position to continue fighting.
I could go on and on about this, but I hope that at least made some sense in short