Well most of the “simple” fuels like charcoal or peat or logs really don’t have much purpose anyway besides crafting a campfire. It’s not like they can be used for making iron or steel, only coal works for that. So essentially charcoal and peat are just substitutes for regular logs, and of course unless you want to make trees more rare as well, logs are not exactly scarce anyway. So about their only use (aside from a onetime component to make a furnace or forge) is for spamming multiple campfires around as a nighttime light source, and I am not sure simple campfires are enough of a high-ticket crafting item to require making charcoal and peat much more rare (since you still have the problem of logs too)
Sorry I think I probably am overlooking your intent and you mean something different than how I am reading it?