Elastic materials are often avoided if you need either linear movement or accurate position control.

Elastic materials are favored if you need shock absorption or no seal system.

Both hydraulics and pneumatics suffer from incredibly shitty thermal efficiency. Electric engine can be 99% efficient. Any single pair of gears or a chain drive can be 99% efficient. Typical hydraulic actuator is something between 70 - 40% efficient. Pneumatics are as bad or worse.

They do use rubber air bellows in paper machinery, but it's being replaced by rigid hydraulic cylinder actuators. With pneumatics you can have somewhat accurate force (== pressure), but you never know the accurate position. With hydraulics it's the other way round. As a result, hydraulic actuators can be mounted in any position regardless of gravity. So you can use the same machinery in various positions.

Edit: here is more if you're interested: https://www.machinedesign.com/pneumatics/primer-flexible-act...