As was mentioned, it IS a thread about why FR is hated. I keep trying to get someone to sell the setting to me but, the only responses I get are either, "Well, ignore the setting material" or "don't use the setting". Neither of which is a ringing endorsement of the setting.
But that's because what many see as a benefit, you see as an obstacle....and it doesn't seem likely that you'll alter your view, or that others will alter theirs.
But I will say that I can understand your hesitation about the perceived need to know as much about the setting as needed. People make complaints along those lines about all manner of entertainment. I think the recent increase in long form storytelling in television and films has really reinforced this whole "you need to watch it all" attitude that we tend to have. People don't start a show on season 3.....they go back and watch the first and second season first. And that's because it's readily available. The same has long been a complaint for comic books from Marvel and DC; the comics have existed for decades, so people were intimidated by feeling they need to know it all in order to jump in.
However, that is merely a perception. When I was a little kid, and got into comics, the fictional worlds had already existed for decades. There were tons of stories, many of which woudl be referenced in the current issues at the time, and I was not familiar with those older stories. And there was no internet to research stuff....so I was on my own. And somehow, as a child, I managed. It really isn't that hard. Most good stories, even those based on prior material, will give you everything you need. My 3 year old daughter loves The Force Awakens, for example, without knowing any of the backstory or other movies. Everything you need to follow the story is in that movie. Much like the original Star Wars; it referenced things that had happened prior, and yet we did not need to fully understand those references in order to follow the story.
So, the appeal of the Forgotten Realms....and really, just about any setting....is the existing material that you can draw inspiration from. As I said earlier in the thread, this can be as minimal as using a map and some location names, or as involved as running a game that heavily involves setting NPCs and tropes.
Let me give you an example from my game that may help. My group started our 5E game with the starter set....I ran them through the Lost Mines of Phandelver. At the time, we were treating this as a trial run to see if everyone liked the system and to let them try a few different character types (we used a pool of PCs and I would let them swap out at times to try a different class or build). We left the adventure in the Realms because there was no reason to change it. We needed nothing more than the Starter Set to play this game. Now, that doesn't say a whole lot because Phandelver can be dropped into any campaign setting with little adaptation needed.
But it turned out that everyone really liked the game, and they really liked the group of characters...so rather than start over, we decided to continue. The campaign then became about what they were going to do with the mine they had reclaimed; the NPC Gundren Rockseeker made them partners in his endeavor. So they decided they wanted to establish trade with other areas in order to sell the precious metals from the mine. So that's when I looked at the FR map to see where specifically Phandalin was located, and then decide what areas woudl make for good trade routes.
So their first step was to establish trade with Neverwinter and waterdeep....both nearby and pretty straightforward. Not a lot of research needed to establish this. I gave them some contacts in each city and we established during some downtime style play that they had trade, and it gave them a basic monthly income of X.
Looking at the map, I thought that trade to the central area of the continent would make for very high profits. So that would be what's called the Heartlands.....the Kingdom of Cormyr, the Dalelands, and the elven nation of Cormanthor. Now, I know only the very basics of these nations. I know they've been the subject of many novels and game products. But I really don't need to know any of that for my purposes at this point. So I invented some NPC contacts for the PCs. They met them and worked out a deal....so now they have to establish a trade route to that area.
So we looked at the map and I let the players come up with a few different routes, and then decided what would be the benefits and drawbacks of each one. I made most of these up. The biggest exception to that was that I decided the Kingdom of Shade still existed in the Aunoroch Desert, and that they would potentially interfere with any trade near that area, or try to claim some kind of tax.
Now....Cormyr, Cormanthor, and Shade all have tons of NPCs and story hooks that already exist. I am only vaguely aware of any of them....but none of them truly matter at this point to my campaign. I don't need to know all the crazy succession stories of the nobility in Cormyr....it's convoluted and unnecessary, so I ignore it. I just use what I like and what I need....I needed an area far away from the PCs' home that woudl serve as a good place to try and establish trade. the Heartlands serve that purpose. I then looked at the route, and found some threats in that area.....Shade being the big one. I don't need to know anything about the crazy backstory of Shade....all I need to know is that it's an arcane society dwelling in a floating city-state that has recently arrived in the world. That concept is cool as hell to me, so I decided to use it; but I only need the basics.
So to me, this is the appeal. There are many options for the FR where you can pick up on a hook or an organization or a location and run with it. You don't need to know everything about it. The basics can form enough for a really cool campaign. Then, if your players really take interest in a certain element....my players really took to the Shades as villains...then you can research that a bit more and add to what you're using.
So I find the amount of source material that exists as a positive. But I also like to take existing elements and make them work with mine. I find it a creative exercise rather than making things whole cloth on my own. I freely steal from settings, and disregard anything I don't like.
But like I said, I don't even think this is unique to the FR; this applies to any pre-published setting. I think it's more a matter of degree. FR does have a lot of material to draw from. For many, that just means more possibilities, more options, more stories....for others, it's more to sift through.
