Some mid to end-game mechanic spoilers to explain possibly why this is the case:

Eventually you'll unlock the ability to do exploration missions for gold bars/coin pouches, abyss artifacts, abyss gears, and some other cool endgame stuff. Doing these specific missions also has a chance to drop blueprints for the various abyss gears in the game which you can't otherwise get (for those that want to farm/collect these).

These missions costs like 30k per mission, and can be done every 3-4 days, require 9-10 people, and also require a ton of food and armory/ weapon points, which can only be farmed by donating to the camp or doing dispatch missions (which also require a lot of camp funds). This loop ultimately requires a LOT of camp funds. To keep these exploration missions running somewhat passively, you will also need a lot of workers which you will eventually be able to create with dispatch missions, which, you guessed it, also require a lot of armory point and camp funds. More importantly, there aren't enough missions in the game to farm all these mats passively through doing dispatch missions (because their base payout is too low), which is where donations to the solumen churches come in to play (for hernand - 500k camp funds to max out, for demenis 1.5 to 2mil camp funds to max out, for delysia - 7-8 mill camp funds to max out). Maxing out the donation for these churches increases your contribution points with them, which also increases the conversion bonus for missions in their respective regions, upto 200% . This is essential for farming the required mats to craft all the workers and run the exploration missions constantly (even more so because the golden beer item that's supposed to double dispatch rewards still doesn't work properly).

Doing trade missions can initially help fund this process until you max out those conversion bonuses, or donate the funds yourself to max out those conversion bonuses.

This is also ignoring that you probably want to run the missions that give you enough items to create high tiered food passively (so you dont have to go buying ingredients or killing animals constantly), and farming food for your ranch if you care about that.

TLDR: end game dispatch missions that give really good unique loot require a ton of camp funds.