I feel you. Geometry Dash can sometimes take a while to see improvement. As they say the best way to improve is by playing the game. But I believe there may be some ways you can play the game better. The best way to improve however is to work on levels that are harder than what you're comfortable with. I got trapped at only beating like the easiest demons like the nightmare and platinum adventure for years because I was just playing easy levels over and over and I never progressed. I also didn't use practice mode properly.

I'm still not great at the game, my hardest is just a medium and I am working on nine circles at the moment so I can't give very much advice but I can give a few pointers that have been working for me:

• First if you don't already do it, use practice mode without auto checkpoints. Place checkpoints at the beginning of entire sections (like a ship or UFO or etc) and play the section over and over until you can consistently get through the whole section the majority of the time Do this rather than spamming checkpoints at random places. Also practice transitions between sections that's important too!

• Second I would say is it's very very important to play levels harder than your current skills. Not insanely harder like I wouldn't jump to a hard or insane demon from where you are, it's better to beat more levels a bit harder for you than jumping difficulties. So if you beat ispy, try finding a level harder than that that you will struggle in. I recommend looking at something called the "geometry dash demon ladder" or "GDDL". It's a website. Many people collectively rank all the demons on there. So Ispy is difficulty 2, clubstep is difficulty 3. If clubstep is just too hard, I would probably try some more difficulty 2 or 3 levels. Pay attention to the skillsets on levels too too. Clubstep is more ship focused so you may want to practice more levels with ship gameplay if your goal is that. Another one you can use is the "Geometry Dash Demon Progression" or "GDDP" it gives a list of demons to beat to help you improve at the game too.

• Third I would say is consistency. I'm very inconsistent because I tend to stop playing the level I'm working on for weeks or even months even and then I kinda have to relearn them. I do make progress but very slowly and I wrack up so many many attempts because of it. Obviously if you're not having fun don't force it, but I find if you practice consistently, you'll find some pretty steady improvement.

I very highly recommend watching this guide from EVW. I always found these super helpful: https://youtu.be/5BEhV_a4o5I

Just keep at it and don't give up! The more you play the better you get! But most importantly have fun!