I don’t think that’s the case. In my country (UK, and specifically England) it’s generally not permitted to go wondering around the countryside unless you’re following a route that is a legal right of way (typically a Public Footpath or Public Bridleway). Often these are poorly marked on the ground and depending on the terrain and level of usage, there may or may not be much evidence of use on the ground. Nevertheless the legal right of way exists, and for countryside walking in the UK it’s necessary that they’re shown on maps and available for routers.
Hence it is useful that such routes are mapped as footways/paths/bridleways, with additional tags to record their surface and visibility. If maps were to stop showing them and routers stopped routing over them, it would seriously degrade the quality of the map in England and Wales. We already have sac_scale=* surface=* smoothness=* and trail_visibilty=* to capture the various aspects that might matter to users. What advantage does something like highway=pathless have over proper use of these tags?
If people are put in danger by following a marked alpine path in the mountains without properly assessing the conditions, then I think that’s on them (or potentially on the map/router provider for not making use of some of the other tags in our data). If you’re on a mountain you should expect paths to not necessarily be marked/visible, and the paths shown on maps to be the better routes to take given the situation on the ground. If it’s possible to get a a summit, then it’s arguably better to show the least worst route then nothing at all. On the other hand, a perfectly usable and safe public right of way route across open fields in the UK is not shown on a map or available to a router, then that just makes our map look stupid.