Don’t forget games played on a 2d plane but rendered with 3d models and cameras! Those are also called 2.5D
For example Factorio where it uses 2d rendering techniques like sprites which are pregenerated from full 3d models.
the classic example is "pandemonium!", a 3D platformer that only allows you to move on two axes. you move on the surface of an imaginary ribbon winding through the 3D space.
i've never heard 2.5D used to refer to that, i've only heard that used to refer to games that are rendered in 3D but are played in two dimensions, (where that wouldn't be assumed, so excluding, say, a tennis game.)