Keywords are great allies to increasing your chances to be suggested to a potential audience that would like to watch your content. Using searchable keywords and keywords your peers/competitors are using, is useful to having your content exposed to relevant audiences that don't know you yet.

The strongest place to place relevant keywords will be your title, then your description to strengthen SEO, and finally, your tags

Some creators believe that there is no need to care about your tags, but they can be super helpful to tell YouTube which new audiences may appreciate your content. Use similar tags your peers are using, and misspelled words that people can search, such as “a lot” or “alot”.

If you don't effectively use keywords to describe your video, YouTube will be forced to rely on extrapolating from your existing audience to find new viewers. This can be particularly limiting when introducing new topics on your channel that you don't have a history with. i.e. a new game, a new challenge or trend, current events, etc.