Mapping individual steps as separate areas? That’s a step too far in my opinion. A smart 3D rendered should be able to interpolate based on incline and step_count and width.
Also some tagging errors: nature=scrub is uncommon in residential areas, the mapper likely meant “bushes” or a wide hedge. Also used leisure=garden for what was likely meant to be landuse=flowerbed.
I appreciate the mapper’s enthusiasm, but I’d rather see that energy invested into improving other aspects of OSM, there are many regions where the basics (POIs, house numbers, and even major roads) are missing.