It's called a game ban, and there are several possible reasons for it.

No one can tell you the exact reason.

The ban is permanent and cannot be removed.

引用自 S1lver：

Hi today I go and play cs2 suddenly I see Ive Banned. I want to know why Ive banned I Didnt use cheat. I play cs2 for fun I like cs2 and I never use cheat in cs2. please check

1 game ban on record | Info
0 day(s) since last ban

you want to know why, go to your profile and click on the info button next to your gameban. Irrelevant what it says ingame, as per your profile you have a gameban. There are a few reasons for a gameban. FYI this is a community only forum and not an appeal forum

Hi! Totally get that this is a shock: you just log in to play CS2 for fun and suddenly see a VAC ban on your account. But VAC works with a delay - the ban is not about what you did ‘today’ but about some earlier moment when the system detected suspicious software or interference on your account, and it never reveals the exact details. Steam Support cannot remove a VAC ban or tell you which program triggered it, and any bans that were truly issued by mistake are automatically reviewed and removed by the system itself if it decides they were incorrect.

引用自 krqmed：

Hi! Totally get that this is a shock: you just log in to play CS2 for fun and suddenly see a VAC ban on your account.

In the three posts where I also replied, you only talked about VAC bans, but there were two cases of game bans and one case where there was no ban at all.

This doesn't help anyone; it only confuses the affected users even more.

引用自 Lufia：

How about you stop mentioning VAC bans in every single topic?

The last three posts of yours where you only mentioned VAC bans were about two game bans and one where there was no ban at all.

I think they are using AI to generate their replies.