Streetwise, being the functional equivalent of Gather Information (with a dash of Knowledge: Cities splashed in) suffers the same problems its analogues suffered in the previous edition: said information being gathered is usually critical to advancing the quest and/or story. Since a failed skill check should never keep the plot from moving on, DMs got used to providing said information gratis (or attaching it to a more generalized skill, a la Diplomacy) and players got used to having such information provided without having to shill out for the skill.
Truth is it's much more difficult to include clever (but not necessarily vital) ways to include Streetwise into skill challenges. In my estimation it boils down to the kind of campaign you're running. Some games (particularly urban campaigns, or where the characters have to play detective often) would get a ton of use out of it; other games would rarely see it used at all. That said, it does appear to have some fun skill powers. If you ever wanted to play an Aladdin-esque character, there's your skill.
Thievery is similarly underutilized. I think there exists a mentality that Thievery encompasses the classic Thief skills (Open Locks, Pick Pockets, Find/Disarm Traps) and that's about it. The skill itself can have far broader use in any skill check or challenge that requires any sort of manual dexterity. I recall the comic from the PSG about the character who learned to pick locks in a macrame club. This idea can be reverse-engineered, and suddenly your thief is a natural talent at anything that requires a sharp eye and nimble fingers. To adventurer the classic Thief skills are probably going to be the most often examples of such use, but they don't have to be the only ones. I remember a story (I think from ancient literature; though it may have been from a modern novel I read a few years back) where a hero was given only one opportunity to pass a thread through the eye of a needle at arm's length. You might make the argument for perception (which everyone is going to take) in this particular challenge, but I'd likely give more bonuses to the player trying to use Thievery here.