I think there is something in this thread that is just not connecting with you. Also, let me preface this by saying I am not HALF the player that many on this forum are, but I’ve learned a lot and I hope maybe I can help you too.
The motions we’re talking about in regard to picking are not remarkable motions. They aren’t something only a select few can do at high speed. Knocking on a door, erasing on a piece of paper, tapping a pen on a table, etc are all motions that are used in various forms of picking. You didn’t have to start knocking on doors really slowly and then with practice you were able to knock at a reasonable speed. You could just do it. All of the motions can be done easily at speeds we’re talking about for picking. The speed test videos that @Troy and team have posted recently are a fantastic way to demonstrate this. You don’t need natural talent to test a motion at high speed. Barring any kind of physical issue that would prevent you from making those motions, anyone can do it!
I 100% understand how Troy’s advice to try a bunch of things until something “magically” feels easy could be discouraging. I’ve thought the same thing before. Like, “Yeah, sure, that sounds great to you, but how is that going to help me? I need steps!”
I’m a lot like you. I’m very analytical and was looking for step by step instructions to fix my problem. Unfortunately, the truth is, those don’t exist. When Troy says it “magically” feels easy, he isn’t just saying that now because he can do it. That is really the case. I didn’t start really improving until I stopped trying to make specific motions and started just trying things until it felt easy.
By trying things, I (and others) am referring to altering the way you’re picking. Change your pick grip, change the angle of your arm, change the angle of your pick, try some forearm rotation, try some elbow motion, etc. Keep changing things until something feels super easy. For me, it literally feels too easy. Like so easy it’s really hard to control. I always have to warm up a bit, but once I’m warmed up, I seem to fall into the correct motion and it feels easier than I ever thought possible and my accuracy goes straight out the window, haha, but that is improving with time.
My point is this: you can absolutely do it, I have no doubt whatsoever. However, you may have to let go of your analytical approach to it to see the progress that others are seeing. And don’t worry, the irony of me telling you to be less analytical on a website entirely dedicating to ultra in-depth analysis of picking motions is not lost on me, lol. I had to do the same and it was genuinely one of the hardest things I’ve ever done with my playing. Not thinking about it and just moving around until it felt easy seemed completely foreign to me, and frankly, really stupid at first. But I eventually found something that works for me and if I can do it, you definitely can too.
Andy Wood described it like learning to ride a bike. You can’t really describe to someone what balancing on a bike feels like, and when you’re learning, no amount of thinking about how to balance will ever help. Once you get it, you do it a bunch more times so it’s a repeatable habit and you pretty much never forget it, hence the saying “like riding a bike”.
I hope somewhere in these ramblings of a former overly analytical guitar player, you read something that at least helps somewhat.