How many members of your congregation are taking organ lessons? How many have pianos in their homes? Probably far fewer than a generation ago. Some congregations are getting desperate to find competent organists.
If the trend continues, we could consider going back to unaccompanied singing, typical of the early days of the Protestant Reformation. It's likely, though, that few congregations would have much success with acapel-la singing. Our culture is simply not a singing culture.