navigation and OSM's main map guidance needed

I have a minor issue involving a shopping center with a highway=service roads connecting to a primary with only building=yes presented inside. Just a simple area with minimal tags/points etc. I noticed if I right click and select an area inside the shopping center, it sticks to the primary road it is closest to. it will not let me create directions from the connecting service roads. If I add a node and tag it as “Target” then try to set a point for directions, it will stick inside the area from that node. I also noticed if I were to click on a residential street with no other POI near, it sticks to that road I randomly click on with no problem

so from my understanding, since the service road connects to a primary it won’t favor the service road even if I need to travel onto it to reach inside the shopping center? it will only set directions to (or from) a residential road or higher type?

now things get really confusing…

-why is highway=service heavily used when its limiting in regards to routing? (there are A LOT of areas that are not added to osm yet and are all connected to service roads/apartments surrounding LA,OC, and Inland empire that don’t provide direct routing to actual destination)
-why wouldn’t highway=unclassified not be a more suitable tag since its has more importance? (there are A LOT of areas that are not added to osm yet and are all connected to service roads/apartment complex areas)
-why am I so frustrated over trying to form an understanding from an OSM noob standpoint and the standpoint of everyone including myself, who uses osm data commercially?

okay so how should I approach this?

is it the lack of poi’s for the retail buildings? I have an area=retail and connecting nodes from highway=service to the surrounding area but
I honestly think highway=service is not the best type of highway tag especially if it is the lowest classification to actually use. possibly this is a mistake? but from what I have gathered when researching within the osm wiki, that isn’t the case it seems.

If I can get help from the brilliant minds of the OSM community, I would very much appreciate your time.

PLEASE…

too many question addressed. I apologize

I suspect this is merely a decision by a given routing engine not to route on service roads. The OSM website offers two routers (OSRM & Graphhopper) so it would help to know which one you were using.

Additionally, if the service roads were added recently they may not have been incorporated in the router’s database.

It would be helpful if you could identify a location so that people can check if they can reproduce what you are describing.

It is certainly not the case that routers never route on service roads, here is an example of Graphhopper routing to a point on a service road in a shopping centre car park:
https://www.openstreetmap.org/directions?engine=graphhopper_car&route=36.66873%2C-4.46988%3B36.66796%2C-4.46807#map=19/36.66846/-4.46889&layers=N

As SK53 says, it is possible you are simply seeing a delay if this is an area of the map that has been worked on recently - router databases can take much longer to update than the main map display.