Extremely useful. They are amazing fiber gatherers and while there are better options, they make great berry gatherers with the added bonus of collecting wood and a decent amount of thatch. They also are good travel mounts with great stamina, decent speed and the ability to travel on ziplines as well as moving just as fast in water as on land They are also extremely strong. With a decent helmet they can easily solo a spino of their level or higher even with the spinos recent buff. These guys don't get the love that they deserve.
Possibly the most useful creature to go caving with as his small size but large health and damage allows him to withstand onycs,spiders and scorpions haven't encountered a arthurplura yet so not sure how effective he is against it