BG is based on having photographs taken by user/volunteers using the BG app in smartphones. The photos are loaded to a cemetery with the GPS position tagged to a pin on the maps. It is very searchable in a number of different ways.
You just need to take some time and read a few FAQS.
1. You can't create a "memorial", you can only create a record based on a specific gravestone photograph.
2. Go to Cemetery Map from your dashboard and you can see pins of various colors representing cemeteries in your area.
3. Select a cemetery and when it loads you should see pins for the various graves. Yellow pins have individual records; green pins have not been transcribed yet. Areas with no pins means that no one has taken photographs there yet.
As to the values:
1. You can search for an individual and see the location of the grave, as well as any transcribed or contributed information.
2. You can add information to an existing records, for example - add your grandparents marriage date if you know it from family records. Or their immigration/naturalization date/papers. There is a way to add supporting docuemnts to family history.
3. You can edit if you know the information there is incorrect.
4. You can search for cemeteries by name/location or you can use the cemetery map to locate a cemetery.
5. You can add a cemetery if you want to take photographs there and the cemetery is not already in the BG database.
HOW TO do these and more - answers are buried in the various pages of BG, including FAQ and hundreds of posts here in Community. Take some time to read/study and you will see that BG has great value.
And; it is not the same as Find-a-Grave; that also has value, just with different approaches.