There are various mechanics changes which could be made, don't get me wrong. But reducing the game to one stable and one testing continent would be a good start at getting it off life support to buy time for the changes to be made which might enable it to attract new players. Mortality would be a great change to make but it, like so many other things, would be part of a long term fix.
Right now the game doesn't need tinkering with, it needs electric shock therapy. Cutting losses and closing continents will improve density and make it much more fun on the remaining one or two continents. That's the kind of treatment the game needs. Working on a long term recovery is pointless if the game dies before then anyway.