it could be a robotic arm
with a giant router attached to it,
to cut the wood,
but disadvantage, many moving parts,
across different axis.
makes it permeable to damage,
and makes it expensive as well.
so the cylinder,
is faster to cut,
less components, while limited in its axis,
it need not have so many axis of movement.
it will cut the tree, and dodge the falling tree,
move to the next.
however, if the horizontal cylinder,
suddenly turns vertically, and
descend down to meet the branches on the fallen tree,
it may remove the tree branches.
so the cylinder, having some angles of movements
will certainly be advantageous. but not as susceptible to
damage as the robotic arm.