Diablo 4: 9 Changes Blizzard MUST Make
3. Make Gems Exciting
What would you rather? An upgrade item with magical properties that, when infused into your armour, bumps up a few numbers on your character's stat sheet, or triggers a change in an existing skill that mutates your playstyle in ways you hadn't imagined?
Needlessly convoluted it may be, but Grinding Gears' Path of Exile has the right idea in this department. By all means, make climbing the XP ladder the core method of unlocking new abilities, but let players supplement that progression, not with arbitrary boosts to health or strength, but tangible benefits.