I think you may be confusing content policy and user moderation with countervandalism. The social hierarchy arose to resolve legitimate editorial disputes and address the sort of behavioral issues that any online community encounters. We have these social structures too, only more implicit and ad hoc.
On the other hand, Wikipedia primarily employs technical measures against vandalism. You may be familiar with page protection or semi-protection (against new and dormant users). It’s easy to see why this mechanism would be incompatible with OSM at the data model level. But there are also a number of other layers of protection, including:
- All manner of API rate limits
- CAPTCHAs, though they are a mess
- Personal watchlists for closely tracking changes to specific content
- Built-in tools to visualize edits and revert them, available to any user
- Banning IP addresses and ranges
- Abuse filters (akin to the DWG configuring the OSM API to automatically reject any changeset that matches an Overpass query, and optionally automatically ban the user too)
- ML-based revision scoring (akin to OSMCha labels)
- A legion of supervised bots run by the community, some of which are empowered to revert on sight
- A concerted effort to detect and block open proxies (trading off the ability to edit via Tor for protection against botnets behind VPN)
- CheckUser (akin to the DWG hunting for patterns in users’ IP addresses etc. upon suspicion of sockpuppetry)
I think it would be hard to argue that any of these technical measures has hampered Wikipedia’s editor recruitment and retention, except maybe the overuse of reverting or the ban on open proxies. For perspective, Wikipedia still welcomes anonymous IP edits, a practice that OSM banned in 2009.
I don’t harbor any illusion that implementing any of these measures would be easy or even feasible in this particular moment. But I’m pretty sure we’ll eventually end up with something resembling them. Wikipedia went many years with a lightweight trust model like OSM’s, but eventually there came a time when the burden on bystanders began to justify something slightly more draconian.