It's an understandable impression, but it's wrong. There are novels, in which the protagonists, as in commercial fiction generally, largely win out in the end. But throughout the lore there are many times more examples of evildoing that's either not dealt with at all or by PCs in modules; and the published lore mentions a tiny fraction of all the many-stranded happenings in Faerûn.
There are also many more evil and self-interested power groups than good-aligned ones. Here's another example of the difference between the Realms and its presentation: a closer reading of the sources shows that they consistently over-stress the well-known (to us) groups over the smaller, local ones such as merchant cabals, whose combined influence is just as important.
There are also many more evil and self-interested power groups than good-aligned ones. Here's another example of the difference between the Realms and its presentation: a closer reading of the sources shows that they consistently over-stress the well-known (to us) groups over the smaller, local ones such as merchant cabals, whose combined influence is just as important.