the issue is, that schools must filter all forms of communication, according to CIPA, a law that is in place to prevent students from accessing questionable content in schools. There was a time when we had to block google images here, because the content filter couldn't force safe or strict filtering on search engines. It was the only option we had until we got a different content filter.
Now with the one we have, it allows us to have google image search open, while it forces strict search, no matter what happens on the client side.
The reality is that as a School IT admin, I'd rather not have to deal with blocking any content at all, but it has to for two main reasons. 1) the law says we have to, 2) there is only a limited amount of bandwidth we have that can be provided to the school, and we have to ensure that access can still occur for everyone.
As said earlier in this thread, if you must have access to stuff that is blocked, do it at home. You can wait 8 hours or whatever it is to do your stuff at home.