First of all, you need to imagine our eyes working like a camera, all parts of the camera from the external aperture and shutter to the internal lenses and film have to all be well-functioned to give you a clear image. It is akin to our eyes from the cornea all the way to the lens and ultimately the retina. Every structure in the eye has to be in a healthy state to give you good vision, regardless of whether you have cataract surgery or not. In short, the answer would be a yes to your question. Deterioration in vision is multifactorial which could be due to other underlying eye issues like age-related macular degeneration, glaucoma, diabetic retinopathy, retinal detachment, and the list is non-exhaustive as the eye is a complex organ.
It is therefore important to seek consultation from an eye specialist to find out the cause of vision deterioration. If we are to view this question microscopically for possible causes of declining vision arising from cataract surgery alone, it could include post-op complications like swelling, inflammation, and infection; though the likelihood is low for cataract surgery. In such cases, close monitoring is required and treatment will vary based on severity. Another possibility is posterior capsule opacification in which the capsule that holds the artificial lens implant becomes cloudy due to cells growth. As such, the patient may benefit from a relatively simple procedure called laser capsulotomy to create an opening in the opaque capsule that allows light to enter the eye and restore vision.
