Do you think osu really help with your aim in games like Minecraft, CSGO and more?

Osu definitely helps with reflexes and reaction times but not so much aiming. If you want to practice your aim for CS:GO you should check out "Aim hero" on steam. It has sensitivity options for a lot of esports games which allows you to sync your aim between them. As a person who is quite good at Siege I find it very helpful.

Contrary to what others are saying,

Osu! in a way helps with aim because aiming itself contains factors of how well you tap; let's say certain patterns and jumps, etc. along with sight reading if you're able to master playing low AR maps

However first-person games all have different sensitivities and aim gimmicks like spraying and such so the answer I can give would be pretty vague


However for Starcraft I've heard it does help when you have to do many actions and I'd think that It'd reduce the chances of mistakes being made.

No, Osu will not help with your aim in any game. Reflections doesn't make your aim better.