So I have joined SO 4 years ago.

When you join you cannot comment, you can only write separate answers until you get some amount of points.

Now when trying to add some answer to a question SO informed me that it no longer accepts answers from this account.

The help article says that's because answers provided from this account in the past have been low quality.

I checked, an I have exactly one answer with exactly one vote. That's not much I suppose.

I wonder how I am supposed to raise my points when I can't do anything on the site, though.

Maybe it's a slight nudge to new users to go looking somewhere else. They are not wanted here.