Complex sentence: Many long-time residents, mostly renters, have moved out because they were unable to afford the increasing rent due to rising property values, and when low income renters moved out of the neighborhood, wealthy homeowners moved in.
Split into simpler sentences: Many long-time residents, mostly renters, have moved out, unable to afford the increasing rent due to rising property values. While low income renters moved out of the neighborhood, wealthy homeowners moved in.