Solo grinding is fine. Grinding together is better. Guilds share a multiplier bonus, level up as a team, and split a community treasury.
Small enough to coordinate, large enough to cover every timezone and tier.
The whole guild gets a multiplier bump: 5% at level 1, growing by 1% per level, capped at 15%.
Guild levels come from combined season points. There is no way to pay your way past the grind.
A slice of member rewards funds the guild treasury, governed by members for future events and prizes.