First of all:
If you're looking for maximum image quality, don't use any filter at all. Without exception, every filter has a negative impact on image quality. With good filters, this is acceptable, with bad ones, it's not.

If you want to take photos with maximum quality, you should always use a good "fixed" neutral density filter. Variable filters always have a slight influence on color; you can't circumvent physics in this case.

So, who is a variable filter suitable for?
Primarily if you're shooting videos (where you should observe the 180-degree rule) and you don't want or can't go through the hassle of changing filters. For example, when traveling, with family, etc., or simply because of the convenience.

In this context, the filter fully serves its purpose.
The feel, material appearance, rotating mechanism, and above all, the optical quality are all very good within the possible limits. The mechanical limitation of minimum and maximum darkening is extremely pleasant in practice. You know without looking that when the filter isn't actually needed, for example, for a photo, it's set to the minimum setting.
Because you don't really want to be constantly screwing filters on and off.

This is where the alternatives come into play:
Magnetic, non-variable ND filters. They can be put on and taken off quickly and easily and offer higher optical quality. However, they also cost considerably more.

One disadvantage of this filter is that you can't attach a front cap. Otherwise, the mechanical design would greatly increase vignetting, which is otherwise visible (Nikon 14-30), but remains within acceptable limits. Magnetic front caps, however, are obviously available for magnetic filters.

This filter is good; it's not a cheap filter, although it is much cheaper than a set of separate magnetic filters with fixed ND steps.

So before you buy, you should compare, and if separate filters are out of the question, this variable ND filter offers a really good alternative.