One of the few file managers that manage to look good *and* function well. Most 'modern' file managers are either slow, very feature incomplete (Files doesn't yet cover all my bases but comes real close), or a combination thereof. Most traditional file managers (especially on Windows) have a clunky UI/UX, and/or have way too many extraneous features (contributing to aforementioned clunky UI, paired with pre-UX oriented guis), cost an arm and a leg, or have other hangups.
Files can also reliably replace Explorer, whereas many non-paid file managers don't integrate right, or worse do it in a way that messes up Explorer.