Here is a a few issues I have seen:
Why? Why are people going to fight? There is very little real benefit when you distill it. You get shards…okay so I will apply this to diamond. You get riders who make your dragon, Noctua (the new Phasmos btw so solid work there) stronger. Okay…so a decent flier with no runes and no rider is going to take pretty much any base if undefended. However, with defenders, even with the best runes and rider, that dragon still dies. The outcome is super binary. So…essentially for practical use, you are doing all of this work for NOTHING. Yes, you get shards but they actually have very little effect on outcomes in the game itself
Next we have balance, we can start with attacking. There is very little true benefit to it. You have to fight somewhere that, best case, there is no active bonuses and you are just evenly matched. So, you “win” that battle, great…now you have an island that 90% of the game can’t defend against if a max player just buys millions of boats and with little skill just throws 2-3 maxed obsidian tier dragons at in a clear display of money > skill. Defense needs to be improved to slow this down and islands need to have value. Enough value for people to be willing to attack for a real, tangible gain. Not so they can win an island they are going to lose again 6 hours from now.
When it comes to balance, if you want people to actually hold islands, maybe increase the ratio for defense higher than the cap on offense? That way the island has a real benefit and someone has to make a real choice of being willing to attack for specific gain. Not just because they happened to want PG’s balance sheet to look better (although from PG’s standpoint I do get why this is appealing)
Motivation, just going to be honest but this coming from one of the better teams, there is no game related reason for teams of a higher rank/strength to fight each other. It is a system built so that your best return comes from finding the smallest team possible and annihilating them. There has to be some value a team can have to deter this or at least slow it down. Have an incentive to hit higher? Better prizes for that? Better island value? Not sure but the current system clearly doesn’t work.
Finally, Alliances…while I am not a fan of them at the end of the day they are a part of it. One thing that is SUPER frustrating I am sure. PG has said repeatedly that Alliances are important to them and to Atlas…yet, this burden has fallen completely on the players. There is ZERO in game support for any kind of alliance and in fact one could argue in order to make an alliance work you are actually working to overcome the mechanics of the game to get this done. I am not saying that there will ever be full integration but for something that is said to be integral you need some sort of developer support, other than simply the words.