It would take a pretty dramatic turnabout on some design decisions to bring most of my guild back. The vast majority of us have written Crowfall off and moved on completely.
However, here's a list off the top of my head of what I think it'd take to get us back:
Reduce the grinds to a level where a guild can focus primarily on PvP.
Replace the godawful RNG-gated discipline-finding system (it's terrible in 5.92 still) with a proper crafting system for them
Improve performance in large fights
Remove the target cap on area-effect damage to let us bust stacks of players. The blob vs blob fights are custard terrible.
Reduce out-of-party area-effect healing and shift the healing focus to self-sustain and party-only / targeted heals (more stack busting).
Give better telegraphs so that we can get some player-skill based combat going with counterplays.
Improve the combat UI or give us hooks so we can write our own (WoW was so good at this)