1.7. Best PVP ever. 1.7.9 if there is one. Also 1.8 is good, but doesn't have the block hit. But you can use mods so you can block hit. I play 1.8.9. It's good for me. I have mods for block hit, so it's good.
Minecraft is not dying, it has more players monthly than Fortnite for example, 1.7 has best pvp, if your in Survival, go on 1.13, it really depends on what you like to play
1.13 is fun for survival since you got more risks, but also a bit more rewards with what you can make.
The water mechanic update and introduction of the conduit is very useful. It also helps with designing underwater bases since they now have more realistic water flow