You may be theoretically much better than you are physically. As is the case with me (especially the last year/year and a half) and even though I'm not playing anymore, I used to be much much better than I am now.
I would say you are theoretically better than you play if you can recognize good play and separate it from bad play.
I would absolutely take critiques or advice, even from a lower tier player on my play, simply because they just might know something I don't when they're on the outside of a game looking in. Just watch any stream. When people have the information and aren't in the stressful situation of playing the game, they're much more tactically and strategically aware. These are people who are probably majority bronze/silver that, without the stress of a game are thinking like people in platinum or diamond. You see it literally all the time.
My physical coordination and reaction time was kind of obliterated by 18 months of depression that started about 3 years ago. And I haven't really recovered much of that aspect. It's utterly infuriating when your body can no longer keep up with your brain. Something as simple as "Okay, if Malphite ults, I have my finger on the flash key ready to dodge." and then fucking it up is demoralizing and indicative that I'd probably never be good at the game again. I could probably never climb out of silver now because the hands just can't keep up with the brain anymore.
There was a disconnect that happened when I turned 27 and I so far have never gained it back.