I think we need to know because if we don't know how powerful the druids should be, then we can't adequately judge how much of an acheivement it is that the cult is a threat to them. Yes, the cult is stronger than them, but the cult would also be stronger than a group of hippies. If the game wants us to take the cult's superior strength over the druids as a meaningful indicator, then they should give a clear indication of how daunting a challenge druids typically are in the setting.

I grant you that we do have that map, though we don't actually see it until far into the game, probably well past the point we'd be trying to decide to back the cult or not. And though it's wide, it's not like they're doing anything with it beyond preying on travellers.

As for the question of information, enough information is the amount of information we need to properly understand the stakes and plot points presented in the story. Again, needing to put information together is a good thing in a game, but to me it feels as though we lack ANY information about the wider setting. In particular, we don't know what our character should know. I don't know what average people think of druids, I don't know anything about the gods of the setting, etc. And I'm not even just saying that. I have no idea how druids function in this setting. Should my character know what they are to begin with? Would they have met other druids before? Are druids a thing that people commonly know about? Let me give you an example I used in another forum. The tieflings we meet tell us that their town was pulled into hell. How common an occurence is that? I can obviously assume that it's unusual, but how unusual? Is it incredibly rare to the point of being unheard of? Or if I'm an adventurer, will dealing with hell and devils be something I'll face frequently even though common folk don't?

D&D is getting more mainstream and if you're getting this game then you probably know at least something about the game, but that doesn't excuse the game from giving us as players a baseline understanding of the setting. Like, Gale is from Waterdeep, and we can't ask him about what Waterdeep is like. We also can't actually ask anyone what Baldur's Gate is like. Everything is pointing us there, I can assume that it's a big city that's somewhat important, but that's it. The game isn't doing anything to actually build up Baldur's gate and make me excited to see it.