Address on area, on point or both?

I found multiple buildings marked as areas and on top of them there’s point with an address (e.g.

Wouldn’t it be better if address was part of the area and there wasn’t a point? Or is there some advantage in having both?

That depends on whether the address applies to the whole of the area.

A building (area) can have more than 1 address (different street names with different housenumbers).
You can put the address node(s) near the building entrance(s).

There can be also some formal rules - in Poland an address is attached to a building, not the area (it’s a general rule - there are also some exceptions, of course). In other countries there can be other rules however.

Oh, and by area I mean a thing on the map that is created using “area” tool. In this case – building.