Oh gods no. Unless the setting is industrial age at least, no one is going to take the time to teach the fieldworkers, peasants and laborers how to read. They just don't need it. Not even all the nobility will bother.
Wizards aside, what does the party really need to read? Who in the campaign setting is actually making time to make parchment or papyrus and scrawling out notes or letters to the one other person in a 50 mile radius who can actually read it? 5-15% of the population, tops.
No literacy at all may be a bit much, however.
As for languages... for me, Common goes out the window. Its a very sad shorthand, and I think it loses quite a bit if you can understand everyone around you perfectly well. I've got eight distinct human cultures with a some overlap in places. 6 different languages and 2 dialects isn't that bad. Plus maybe a High or Old version for 2 of them. But since one language will overlap the main 'civilized' areas pretty heavily, and be relatively common in some other areas, I don't think it will be all that bad.
I'm quite willing to give all adventurers two starting languages (+ int bonus and skill points, if they want) since they are one of the few people that travel widely.
Of course I don't have dozens of non-human races running around either, so the sheer level of random insanity isn't present in my homebrew. I think I still top out around 20-24 languages total.