The film was shot using handheld cinematography, which is the most common filming method for beginners, especially for users of this type of vintage camera.
If handheld photography is not handled well, it can easily cause the audience to feel dizzy, leading to nausea after watching for a while.
That's why modern movies, even when trying to simulate the authenticity of handheld footage, will use stabilizers.
Stabilizing a shot has always been a challenge in film production. Common rail systems have to be laid out in advance and aren't practical in complex environments. Most cinematography still relies on Steadicam vests, which involve wearing a heavy and complex device to stabilize the camera's lens.
No wonder the whole industry turned its attention to handheld stabilization devices after some drone manufacturers developed them.