Is PvE, as a whole, still alive?
Well, loot is always a driving factor.
People like me with limited playtime/week need to utilize their time. Result; we prioritize high reward contend. I love the game ad a whole. Even queensdale has a lot to offer. But Im not given a lot of incentive to prioritize those maps in ym very limited gametime over CS, MultiLoot-Basin, and fractals. And I think a lot of people share a similar sentiment. Whether they just need the money or dont have enough time for unrewarding content.
PvE will always be more alive than wvw or pvp imo. However, with the way the heart of thorns maps are designed what you do will probably depend on what time you log in. ANET is getting better though with blood stone fen.