That is true, but don't forget there's a lot of factors that'll make getting more than just 1700 essence from a single batch of 10:
- One or more characters are Eddies (much more essence from those)
- Using XP and/or evo shards to level up and evolve (can easily double essence per character depending on how much you want to invest)
- One or more characters are Gunner/Assassins (a bit more essence compared to Warriors/Magus/Sentinels)
- One or more characters are 4 star or 5 star dupes (that can massively boost a single sacrifice to a higher tier, or you can save multiple high-rarity dupes and go for the higher quantities/more exclusive rewards that are available at higher tiers)
- That sacrifice could reward you back one or more Rare Souls (which effectively is another chance at a high-rarity character, or bare minimum 10% more essence than what a pull otherwise looks like)
Since a lot of long term players are still swimming in Gold and XP/Evo shards (at least the lower tier stuff), a bit of busywork can massively improve your fodder's sacrifice value, which could halve the character investment needed for your next Vortex. It's definitely true that the result still could be a small pile of materials that you don't need, but it could also turn into a Rare Soul that could get you a Valkyrie, or a different Eddie or Ally you don't have.