Factioning is quite brutal on both ends. Unfortunately, I never experienced the days where about 20 greaters got you to ally, but I have factioned over the past 10 months, give or take, to increase both dragon and giant.
If you do it casually, you practically never get there, and if you faction very actively, you are left thinking, "wow this better be worth it." And when you do finally get there you realize it really was only for a couple minor upgrades.
I'm not bashing factions completely, but the ornate rewards for faction are lackluster for the most part. At 65, you basically have to farm light blue dragons in GD if you want to increase faction. Or if you prefer to group you can get hundreds of fangs from East wastes which is not good exp. And your last option is to do EDHK, and this area IMO is not good exp coupled with a very low drop rate of scales.