You think getting stronger or faster is only about bigger muscles.
In a car, that makes sense. The car with the bigger engine is going to be more powerful, simplistically speaking.
The process in a human is different. You look at a stronger or faster person, and you see a lot more muscle on them than on you. And make the obvious connection - more muscle = more strength.
That's not wrong.
But the hardware upgrade i.e. building muscle is only part of it. There is a significant software upgrade that happens behind the scenes.
Your brain and your body don't know to communicate well with each other when you start off. You don't know to keep your chest up or your back straight or brace your pillar. That comes with purposeful practice. That comes with quality repetitions.
As the software improves, the outcomes improve.
And then, you will see a spurt in the hardware improvement.
That's why focusing on quality, on your mindset, and ensuring you are focused and concentrated are all key to seeing results from your training.
It is not simply about lifting weights and then going to your phone and wasting time, or chatting with your buddies until it is time to go again. The more switched on you are, the better.
Focus on what you can control. What you control is your focus and concentration and quality of effort.
You don't control your muscle growth or your physique - at least, not directly.
Do the work. And the hardware upgrade will happen. The outcomes will happen.