It would be nice if they could unlock some kind of noncombat utility ability for each maybe, like entertainer being able to distract people akin to minor illusion or noble being able to summon a servant or urchin being able to beg for gold or something.
Because your noble character just happened to bring a servant along to summon, while being kidnapped, implanted with a tadpole and crashing into the wilderness?
I just assume that my "background" influences the various nature, history, religion etc. rolls that come up both in and out of conversations.
As noted, your race and class are generally obvious to those you interact with - background is not so obvious, unless you are somehow blatantly "advertising" it. Even then, just because you act aristocratic and noble, doesn't mean you aren't just good at faking it. Next time you are in a city, look at folk passing by - that guy in the suit - is he a lawyer? stockbroker? salesman? new grad out on an interview? or is he a plumber on his way to a wedding? And if he's a stockbroker, does he have an MBA or is he a high school grad working at daddy's firm?
While I am sure it is possible to code various responses and situations involving all the various backgrounds in the game, time/cost principals will always come into play - it's more effective to stop at class/race/sex for the most part, and focus other efforts into other areas of the game - combat, spells, game mechanics and the like.
There's still plenty going on even with just race/class/sex. I'm in my first run as a drow, and there are boatloads of distinctive conversation/event trees that did not crop up as an elf, human, dwarf.
And we are still in EA, in a rural wilderness setting. I can imagine plenty of other opportunities once we reach more populated, urban settings.
