Yes it's safe to eat raw sourdough starter.
Eating raw sourdough starter is perfectly okay and safe because there's is no bad bacteria in the sourdough starter or anything in the sourdough starter that could make you sick.
However sourdough starter that is raw can be difficult for some people to digest so eating raw sourdough starter could give you an upset stomach, diarrhea, stomach cramps etc.
But it's safe to eat sourdough starter if you want to eat it raw.
Unlike cookie dough and other baking batter that could have Salmonella in it the sourdough starter will not have any Salmonella in it so it won't make you sick if you do eat it.
I've eaten sourdough starter myself when it's raw and I was okay.