There was a time in the US when property was cheap and there was a lot of people coming in too and halls had too many people. Things are expensive nowadays so convenience will have to be put aside and people will need to travel to get to the hall. Congs need to be consolidated for financial reasons, I’m just guessing.
I will say that it appears that people nowadays don’t have the interest and fervor and excitement to join a religion in response to the preaching work and coming into the JW. Not so inclined.
In the generation will not pass away era, the excitement of the end coming and the cut off dates was a catalyst compelling( and the new teachings about jesus not dying on the cross and the trinity, etc) people to convert but Christian living theme of study presently is not very interesting.