My suggestion is based off of Monster Hunter really, which I believe is the future of boss fights/combat in games.
It would be cool if big monsters/bosses had different parts on them that can be destroyed, and drop different crafting materials (like a beak or tail), and in turn this would weaken the capabilities of the boss.
It also encourages more organised team work in a party/raid, getting people to focus different parts to make the fight easier.
Still don’t know how combat works in the game yet though, so this might not be possible at all lol. but I saw artwork of characters jumping around a massive monster.
Please also let Spears/Lances remain in game.