Tamed Therizinosaurus is the best mount to collect wood, fiber and berries. With LMB you can collect wood as efficient as with Chainsaw. With RMB you will gather fiber without collecting berries, and with C button you pick berries without fiber. Therizinosaurus is a strong creature and can be used as battle mount too, because of their strong attacks. What I found they lack is weight too carry wood they collect. But Queztal with a lot of weight can fix this problem. :)
To get wood, use normal attack which is slashing with claws. To get berries, use bite attack. To use bite attack on mobile, change multi tap to alt attack 2 and tap with 2 fingers when riding the Therizinosaur. To get fiber, use the tickle with claws move. To use the tickle with claws move on mobile, jump when riding the Therizinosaur. Upbote so people can see!!!