I was once seriously addicted to Graal like seriously addicted and you could tell by how many times I tried to quit and every time I came back it was like I could never quit this game. The thing is you do meet people who you grow close to and become great friends which makes it harder to quit which doesn't help lol.
But school is far more important unfortunately for me I've wasted a few years and I became lazy because I cared about getting the next 100k, 200k, 300k and so on pks they were my goals not grades. Now my grades are meh not the best I've wasted a ridiculous amount of time on Graal, I've lost friends in real life because of it because I was to busy playing Graal all day.
One thing Graal has done for me has kept me away from getting into drugs or anything serious which people I knew unfortunately have followed that path and have ended up in a worser situation.
If you're having addiction problems though, play it but every few weeks decrease the amount of time you're on it and overtime you will be on it less and you won't be thinking about it as much.
But I've finally quit it completely and life is much better I'm also a lot happier without it, I have new hobbies, life goals and such, trust me school is way more important but the only way you'll realise yourself is growing up and going through it all.