So I wished to put into actual visual perspective, because I was curious myself, just how much actual content is lost by siding with Minthara, as opposed to siding with the Druid's Grove;
And by looking at such a short summary, it may not seem that bad. But I took some liberty to document every single NPC offering a piece of lore and story dialogue, immediately after the battle without counting the camp scene:
So to put things into perspective.
MINTHARA'S PATH ACHIEVES:
The death of 59 Druid's Grove NPCs
The death of approximately 98 Goblin Camp NPCs (yes I counted all of them)
The death of all 4 merchants on the surface (not counting Zhentarim merchant)
Causes 1 companion to leave (Wyll)
Causes another companion to potentially leave (Gale)
Causes Minthara to potentially die (failed persuasion)
Prevents Shadowheart's romance
All that for a camp scene where we get to socialize with temporarily friendly gobos for one night, a 69 romance scene, an unknown potential interaction with her in the future and a somewhat vague hint on how to approach Moonrise. And that's the best case scenario. Failing a speech check we ALSO lose her. So... literally nothing is gained if that happens.
To me it's an incredibly steep price to pay for so little content and a risk to absolutely have no content.
From what i understand some unreleased companions will leave as well if player picks goblin route. (I learned this reading this forum and reddit so not 100% sure on accuracy.)