If a renderer cannot route the last few meters from the street to the park, an issue ticket should be opened on its Github. This seems like a clear case of "tagging for the router". (https://wiki.openstreetmap.org/wiki/Tagging_for_the_router) The path does not exist in physical reality, and indeed such connections in some cases mislead routers into using paths in parks for shortcuts when there is a high curb in the way, and often street furniture as well.