These are a genuinely challenging and dynamic way to play. No two are alike, and the A.I. actually does give you some real opposition. Island expeditions are like dungeons, available in normal, heroic, and mythic difficulties. That means you can press into higher difficulties for more of a challenge. Of course, the PvP version pushes everything to the max.
Azerite equipment is currently balanced around being able to unlock the outermost, earliest tier of power immediately upon acquisition, while delaying further advancement until the Heart has been further empowered. For example, the first piece of Azerite equipment, gained shortly after the Heart itself, is fully empowered once the Heart of Azeroth has reached level 3. A character at 120 (the maximum for the expansion) may find a piece whose first tier requires the Heart to have grown to level 12 or greater.
For collecting artifact power to level up your Heart of Azeroth necklace, island expeditions are unbeatable. There’s a weekly Azerite goal that you need to meet through the expeditions, and when you do, you’ll be awarded 2500 artifact power. There’s a small chance that you’ll get weapons from completing expeditions too, but they’re not a reliable source of gear.
The power of items depends on their item level, which you can see on the item's tooltip; the higher the level, the better an item will be. However, the Warforging and Titanforging system - introduced in the Warlords of Draenor expansion - means that almost any item of Uncommon, Rare or Epic quality has a chance to ‘forge' to higher than its base item level: Warforging is up to +15, Titanforging is up to +45.
The downside is that War Mode will make you vulnerable to other players, which means you might be killed more often. Whether it’s worthwhile will depend on the zones you’re visiting and how active the other faction is on your server cluster. Heavily populated realms usually mean more players on both sides, and more conflict, but on quieter realms, you may rarely run across an enemy.
But one major question that keeps popping up as players reach the level cap is, "what do I do when I hit Level 120?". On the surface, it would seem pretty simple that your next steps would be gearing up to raid. However, BfA doesn’t exactly make it clear how to go about doing that, and there are more options for future raiders and dungeoneers than ever before when it comes to endgame content.
Mag'har Orc Allied Race Leveling Guide (20-120) Dark Iron Dwarf Allied Race Leveling Guide (20-120) Void Elf Allied Race Leveling Guide (20-120) Best Void Elf Allied Race specs for leveling, efficient zones to level in, and overview of available classes and level 20 starting abilities. Level a Void Elf to 110 for a special set of cosmetic Heritage Armor. Nightborne Allied Race Leveling Guide (20-120) Best Nightborne Allied Race specs for leveling, efficient zones to level in, and overview of available classes and level 20 starting abilities. Level a Nightborne to 110 for a special set of cosmetic Heritage Armor.
Special note: At 110 it's almost certainly worthwhile to go and immediately get your Heart of Azeroth and first piece of Azerite gear from the BfA opening quest. It doesn't take long and provides pretty high power levels. I'd then return to Legion quests until 111 or even 112, since the power of these items will increase your kill speed significantly over the scaled enemies of BfA content.
Mythic+ has some similarity to raiding, but it’s designed for just five players, instead of the 10-to-30 that can make up a raid. This mode tasks players with clearing the game’s dungeons, but with specific changes that make them harder, scaling up until it’s impossible for groups to finish. Players receive a keystone in their inventory that assigns them their dungeon, one of the game’s 10, and gives the dungeon a level. This determines how difficult enemies are and what effects might make them harder. If the group completes the keystone in time, they get a new, higher-level stone; if they, don’t they get a lower-level stone.
At 98 you have the option to drop what you're doing and return to your capitol city to start the quest for your Legion Artifact weapon. However, I do not believe this is necessary to do right away unless you're struggling with kill speed in your current gear. I would recommend waiting for a natural pause, such as hearthing to repair and clear your bags. From 100 to 107 you won't even really fight mobs that often; only just enough to clear the way to any treasure you need to pick up.