IMO, the reason religions will never go away is because every consciously formed ideology or endeavor is already a religion or has potential for it. Just takes adherents to become partly about religion. Add in anything (at all) beyond individual bias, and the religion takes more shape. Toss in concepts by (so called) forerunners of the endeavor that are to be held with great reverence and voila, worship is discernible.
Atheism is a religion. Obviously, it would be a religion that claims zero belief in a god(s), but we already have those type of religions existing. The fact we have self identified religions that are atheistic, makes it then about 'types of atheists' some of which are presumed to be irreligious. Knowing that many atheists probably strongly disagree with my assertion of atheism as a religion, I'll allow them to raise whatever counterpoints they choose to potentially further dialogue whereby the connection, IMO, will be made stronger that it is religious. In fact, it would help my assertion immensely to have that dialogue, whereas no dialogue (of any sort) from atheists, would hinder that overarching assertion.
Scientific practice is arguably religious and science itself has potential as a theistic type religion. I'm sure many scientific minded people hope that potential is never reached, but in some ways it has already been reached, though not universally embraced. IMO, it would be very good if it is never fully embraced for as long as materialism is married to science (and idealism is -allegedly- divorced).
Certain practices of traditional/ancient religions are bound to go away within a maturing civilized society. I think of that as obvious, and not sure anyone disputes it.
It's the conceptual relation with things existing, thought to exist and a desire to organize a framework around that that gives potential to a religion. Once worship / reverence is added into the mix, I would say the potential has been realized of it being a religion.