Industrial shit is really resilient. If they wanted to accomplish actually doing damage they’d have used explosives, but that’s a whole next level of charges if/when they get caught… and that wouldn’t really do much additional good because the company probably has insurance to cover the damage anyway.
This is a visibility thing. The public blowing off steam, such as it were, while building awareness of how prevalent things are.
This is throwing soup at a work of art behind glass. But more direct.
This isn't going to do anything, it's like five hours of cleanup. If you really wanted to shut down the factory you would try to destroy it. If you just want to throw paint then just throw paint.
For what it's worth they did smash quite a few drones and other war-crime equipment. Lighting the place ablaze would be more effective, though that would likely land them heavy prison sentences.
Unscrewing everything they can get to (and destroying the screws/bolts/fasteners) would also be very effective. It's easy to justify replacing destroyed equipment, but working equipment that needs to be thoroughly re-inspected for sabotage takes time.