That is a matter of opinion. If you are writing a term paper and want to be sure the word you have in mind actually means what you think it means, you may look on a dictionary as the authority that settles the matter. If you are playing Scrabble, you may leave it to a dictionary to decide whether a word an opponent plays is really a word at all. In these and similar instances, we look to the writers of dictionaries as lawgivers. They decide what's right and what's wrong.
Yet to lexicographers (and I had to consult a dictionary to be certain I had the right word), they are not lawgivers at all. They simply record vocabulary as it is used in a particular culture. As new words come into use, they are added to dictionaries. As older words become obsolete, they are dropped. Alternate spellings indicate that not everyone spells words the same way. Spellings change over time, as do meanings, so the work of a writer of dictionaries is never done. There is always more history of the language to be recorded, as Samuel Hayakawa might put it.
It used to be controversial whenever dictionaries included slang words or swear words in their newest editions. Critics charged the dictionaries were making such words acceptable. No, the lexicographers would say in their defense, they were only recording the words people are actually using.
I think those on both sides of the historian-or-lawgiver argument are right. Those who write dictionaries should view themselves as historians, not lawgivers. We really don't want scholars sitting in a room somewhere telling us which words are acceptable and which are not, or how each word must be spelled. Yet for dictionaries to have any practical use, they must be looked upon by users as being in some way authoritative.
Before dictionaries, all writers spelled words however they pleased. Dictionaries improved communication by telling us which spellings were preferred by most people and what words meant to most people. Maybe dictionaries are not the law, but to writers, publishers and anyone else who consults them, they provide a common standard that is very much like the law.