Population is way down, competition is way down. Now and then you will get some nice competition, but more often than not its a pro team vs a single or a few semi-pro teams and they wrap it up quickly. CE also plays into that because some players aren't playing other worlds while they play CE, but it's still pretty bad regardless.
I've heard rumors that BD will be making some drastic changes in the coming year (i.e. transitioning to mobile and getting rid of the tick system, becoming a RTS), but only time will tell if these things are going to happen or not and if they would even help at this point.
The reason behind the going down of population is no change in a few days.
i give example:
Imagine a kid. When he/she likes a toy, he/she demands for it.
But when he/she has played with it in a few days, the toy is thrown away.
What I want to say is that you need to keep people interested in one way or another. As i see, there is no one in the whole BD to take care of the newbs in the WORLDs except the ADMINs. Only a few reach to the forums and get help from AANC mentors.
A new system should be devised in BD which should aim at one purpose only "Taking Care of New Players". The human nature is that it goes and stays wherever it gets care and attention.
If the new players will be given enough attention then the population will be like past.
Of course it will be.
Just you need to devise a new system EXCEPT FORUMS.
I made a suggestion regarding this in Community suggestions.