Seeing your recent responses, three things come to mind.
First, watching other players play will always “seem” faster than when you’re playing, simply because of how activated your brain is. You really should watch recordings side-by-side if you’re going to gauge speed like that.
Secondly, don’t just focus on “getting better”. That’s an abstract concept. Pick a specific aspect and try to improve on that. For example, set a goal of “I want to work on landing more safe smashes with my main. My problematic matchups with my main are with characters x, y, and z. So first I’ll research where some openings are against those characters. Then I’ll research which of my smash attacks can capitalize against those openings. Then I’ll play matches against those characters and try to execute what I’ve learned!”
Passively practicing won’t get you very far. Try to practice in a methodical way with a particular goal, and you’ll improve much faster!
Thirdly, pick a main