Why are we still using resistors with %5 tolerance while they can even manufacture a 14.318182MHz crystal?
0.1% resistors are widely available. Digikey lists 59,000 part numbers. But the price is higher, like @ $0.04 in reel quantities, instead of $0.001 each for 5% tolerance. 

If your design needs high tolerance, and your market isn't sensitive to a few dollars of price difference, there's absolutely no reason not to design with tighter tolerance than 5%. 

At my previous job, we used 1% resistor tolerances as a standard, figuring that it was cheaper to spend a tenth-cent or so extra per resistor, rather than do the extra engineering to be sure the extra tolerance is acceptable (or to skip it and end up shipping bad products).

But in other markets, a few cents per resistor (say you have 1000 resistors in a design, those pennies add up) does make a difference. Also remember that any cost difference in the BOM gets multiplied up by a few times by the time the product gets on the shelf at Best Buy.