I think because I grew up lacking close friends, being able to label friendships feels very special to me. I always wanted a best friend as a child, and I did have one before we parted ways, and then my partners came and I consider them my best friends (alongside being my partners).

For example, some people on this site I consider as only mutuals. Sometimes oomfs if I feel that mutual is a bit too formal for them (not exactly based on closeness, but how I perceive them). Other times I consider them a friend (That's on Tetratto though). If they're just a little above a friend (like very), I give them their own sort of status. Like Rodya as my #NiiChan, or Agustine as my #Twin. Another I gave "oomf kun" as it's unique enough, even if it's with "oomf".