With Elsweyr around the corner, it's been nearly 2 years since the release of Battlegrounds, and while they were a great foundation to build upon when they first came out, almost nothing has happened with them since then. A new map here and there has been nice, and there have been a few changes to the MMR system, but no real progressive content to retain current players and incentivize new ones. I love BGs and I play them pretty much daily, and it's very disappointing to see all this potential go to waste.
Several interconnected problems currently plague the BG system:
1) Long queue times - At high MMR, the queue times are horrendous, often making you wait 20+ minutes to get into a match, or even more if you're in a group.
2) Terrible rewards - The BG rewards are just straight out terrible, and you lose way more gold on potions than you ever can make from BGs.
3) Leaderboards based on who plays the most, not MMR, win rate, or skill - Although the leaderboard rewards are usually garbage, the actual leaderboard placing is essentially meaningless and due to the long high MMR queue times, low MMR players can play several games before a high MMR player can even get in one.
4) No long term incentives - MMR is hidden and arguably not even useful to gain since your queue times get worse and worse the higher your MMR is. There is no real ranking system to progress on or real rewards to achieve. Aside from fun, there is no real incentive for your average player to play more than their daily BG every day or to keep working towards something. This ties in with a lot of the other problems and is one of the main reasons the BG population is low. There just isn't anything for players to work towards in BGs. Additionally, there isn't really anything to even objectively measure long term skill progression such as character stats.
5) No lobby system for premades to deliberately fight each other - This is one of the main things other BG players have brought up when I've talked with them about improvements. A lot of solo players complain about fighting premades, but a lot of premades really would like a way to play against each other.
What could ZOS do to help grow the dwindling BG population and expand on the current system? I think to start with, ZOS needs to release some long term incentives, for example a skin unlocked after 500 wins, or an actual ranking/leaderboard system that soft resets every month. There needs to be more reasons for players to start and keep playing BGs. Additionally, some sort of private lobby system for premades to fight each other would greatly improve upon the BG "endgame." In the long run, having some sort of gameplay season where you could register 4 player teams and play against each other with titles/cosmetics as rewards would be ideal.