Landlords do provide services: property maintenance and not having to worry about selling the place when you leave. Are landlords paid way too much for these services? Hell yes. That's more an issue of inadequate supply though, in my opinion.
Similarly, ticket scalpers provide a service, but not to concert goers. Scalpers absorb risk on behalf of the venue/performer. That's why venues, who could absolutely shut down scalpers, don't. Still scummy as hell, but don't absolve the venue of guilt too.