In my case, there was a vscode extension that was conflicting with java extensions and making them very very slow, try to identify this problamatic extension and disable / uninstall it.

I identified that problamatic extension by looking at the extensions tab in vscode, then I noticed there was a small text beside one of them, it was : "extension (...) has reported one message, i opened that message and it said that the extension took a huge amount of time to run, so uninstalling it solved the proplem