Diamonds are appreciated!
The Mushroom People were and are those found living off the land of the Mushroom Planes usually found on islands. If one was to come across one of these people living on their islands, they may find the archers atop the giant mushrooms which dotted the landscape. The job of an archer as a lookout was usually very dull. The most exciting days of an archer's life would be on the occasion that a sea monster was spotted and attacked (who may have found it's way to the islands by chance as no monsters are naturally found on the islands), or if the even rarer occurrence if pirates attacked their lands.
Some say that the mushroom archers had a special mushroom arrow that would release a poisonous spore cloud on impact. This may have been the blue nethershroom native to the nether and which some piglins in certain worlds (known as fungus throwers) have weaponized, albeit as a thrown projectile. Because of this, mushroom archers may have gone on expeditions to the nether along with their mushroom hunter friends and the nether people, but this is unconfirmed.