Aside from being snubbed by many of the “regular drivers” being a sub has some advantages. Being a sub means you can decide what days you will and won’t work. (Of course that risks not having a route that day if they don’t need you!) Regular drivers have to request time off, and sometimes that request is denied!
Being a sub means that you don’t get bored driving the same route every day, listening to the same whiney kids fuss and fight every day. It means you learn a lot of cool routes that you can use as detours later on if a major road is blocked by an accident! And it means that you do not have to wash your own bus! Or sweep it, or empty the trash can!
Yes, I like the advantages of being a substitute driver.