Getting a bit lost in all the discussion on the same topic. 
I’d add a reference to what sounds more-or-less the same thing, perhaps a bit broader:
While I’m a fan of scrambling, I have an issue with it as a separate category. It covers both hiking scale T4-T6 and the climbing scale I-III. Technically, it is already possible to locate it by tags.
Another practical issue is that it will necessarily overlap the actual climbing routes of lower grades. I’ve climbed the last sections of a multi-pitch climb without a rope because it was only II+, for example. Is it a climbing or a scrambling route? Or both?
Which leads us to climbing. The climbing routes may be represented by pathless but that is also incomplete and misleading. Most trad and sport routes are actually not pathless. Well, depends on the definitions on which we can’t really agree, it seems. The routes are usually very well known. They are published in guide books and lately on web sites (the crag, bergsteigen, etc.). Sometimes they have a name plate or the name is just written with a paint. In Austria they are usually bolted and have anchors at the end of each pitch. This really depends on a country as bolting is illegal in some countries but the main routes are still well known.
Definitely not pathless but neither a path. It is something specific - a climbing route. And I’d love to see and map more of them on OSM.
The wiki page
https://wiki.openstreetmap.org/wiki/Climbing
has a section on Climbing Routes but it is not clear to me what is the primary way used to map them.
Currently, people use all kind of tags to add them (i.e. Paths with T6 sac_scale for a grade VII climbing route) and I think they deserve a separate classification.