Imagine JFK, or any other major airport, if ALL the ramp instructions were done on ground control also.
Your smiley "
" would seem to suggest that this is a silly suggestion but many, many non US airports do this. Many have more than 1 ground freq that will cover the ramp and the taxiways in that area (for example ground north or ground south). Then the aircraft on the taxiways and the stands in one particular area are all on the same freq.
There are other ways of doing things than you do them in the USA. Sometimes they are better, believe it or not!