Hello,

Thanks for reporting this.  Two things here:
(1) There is still some nonsense in the way alleys in the park were mapped by different mappers over time.  There will be some cleaning up.
(2) Several ways exist in OSM for routing purposes.  Not having them would mean creating "islands" and navigation engines would not be able to route people across the park, or create illogical detours.  You can safely ignore them in StreetComplete if you don’t understand what they are here for.