Hey, I'm Contri, I have been playing this for a long time and now I'm semiinactive but I see that GH is actually doing something to keep the game working so I'm gonna give 2 suggestions about PvP that I think that could make some old players I use to play with stay in the game and others come back.

1- Add uncaps, kills and deaths to the scoreboard after the LD games. It's something easy and fast and it would give ppl new excuses to show off, and everyone in this game loves to show off. Also it would help to get a better idea of the performance of each player during the game.

2- Make GvG competitive, remove AT from GvG but leave it in RLD (or not, it's your choice but I think it would make it funnier), make the weekly scoreboard based in wins-losses and at the end of each week give the winner guild a sign near the guild name like the LD icon or something like that so they can show that they were the winners and you can also give them a guild furniture trophy or something like that.
The only problem for this would be the subs and farmers, so you could just make that if a player of a team have been in the guild for 2 hours or less that game won't count for the scoreboard (idk if this is hard to program but if it is just think of something similar).
You could do the same for BN

I think that a competitive guild environment would make a lot of playeers come back and some others stay. The last time I asked my friends why they played the game for so long most of their answers were PvP or Guild and I believe this would give players that like PvP an objective and they would farm (or pay) to get the right gear to help their guilds.

Well, that's all I had to say so if you wanna say something say it and that.