How are other people meant to use that area of the park? Children? Female runners? Those right-on homeless defenders dictating to others don’t seem to have been so present in actually found something.
If you let s problem like this subsist (and the extensive pile of belongings indicates he was there for some time) then of course some people will step in to try and do something to reclaim the park for the public.
Most liberal European countries don’t allow things to get to this state. Homeless living on the streets are politely reward by the police to clear up their belongings in daytime, not take over an area of park so everyone else is inconvenienced so ineiersin can squat there.