Despite communicating no information at all about the contents of the question, beginner is the 7th most popular tag on the site.
Some claim that beginner helps guide the type of answers we write. It does not guide the type of answers I write. Moreover, I can't even imagine how beginner would guide your answer writing given how extraordinarily subjective the idea of being a beginner is...
To me, the beginner is code for:
Go easy on me. Also, that complicated but unquestionably better approach you were going to suggest? Don't suggest that. Despite being objectively the only right approach, it's too complicated for me, so don't even bother putting it in your answer.
But I personally just ignore the tag.
We all should be reviewing every piece of code here as if we're about to commit it into our release branch and put it out to a customer.
I work with interns. These interns are arguably going to be "beginner" level. So since they're basically a walking-talking-beginner tag, does that mean I should adjust my real-world review of the real code they're really about to submit into a release branch so as not to what, hurt their feelings? Or confuse them? No.
Don't get me wrong. Reviews shouldn't be mean. Reviews should just be about the facts, which can't really be nice or mean--just factual. And reviews should always take into account the asker. If the asker doesn't get your explanation, it's a waste of time. (But comments can be used to ask for clarification).
But... best case scenario, the beginner tag communicates no information and wastes space in the top 10 tags. Worst case scenario, it irrationally encourages less in-depth answers at the discretion of the asker.
What's worse, beginner isn't even a tag that anyone but the original asker can really fairly add or remove to or from any question.