Buttons are flat text that doesn't look clickable, with the best case of having a very faint border, sometimes only on hover. There are multiple ad-hoc checkbox replacements. There's a jarring cacophony of old macOS and new iPadOS UI elements — old UI elements with small fonts, small padding, and teeensy disclosure indicators share the screen with big fat round blobs lazily transplanted from a touch screen OS. Some elements react to hover, some don't. Some can only be discovered by hovering mouse in a specific location. Menus have varying heights, and varying padding.
Such unpolished inconsistent details used to be a tell-tale of non-native UI toolkits, or skins for other OSes faking a Mac OS X look. Now macOS looks like a hasty unfinished reskin of iPadOS ;(