This card is extremely powerful, but also situational. It is effectively an engine multiplier for run-based effects, which allows you to exploit a limited window where running propels you forward, and hit it two or three times as hard. Because it is situational in when it is good, and because it returns itself to hand when fully utilized (preventing the corp from trashing it along with the hosting ICE) many decks only run one copy to fetch with Self-modifying Code at the right moment.
To take advantage of Pichação, you generally need to run the same server multiple times in a single turn; while you can save a click on your first run, you are often effectively paying a click to install Pichação in the first place, so it takes specific circumstances like being able to use Arissana's clickless install to get any value out of a single run. This line can still be valuable into certain HB and NBN decks that are trying to punish standard four-click turns--hello Oppo Research--or for using Deep Dive, but it's not the upper limit of the card.
So why run the same server multiple times in a turn? Because it can deliver value unlike any other runner economy. Scenario: Arissana has access to R&D for 2 and possesses an installed SMC, along with two installed copies of Aeneas Informant.
Click 1: Slap Kyuban on the R&D ICE.
Click 2: Run R&D. Pop SMC for Conduit. Use Arissana to install Pichação on the R&D ICE. Make back your 2 with Kyuban. Access a trashable card on R&D and make 2 off your Aeneas Informants.
Click 3: Click Conduit. Access 2 from R&D. Both are trashable. +4 total for your run. Pichação returns to the grip during this run, but we still have 3 left to go.
Clicks 4-6: Click Conduit, accessing 3, 4, 5 cards from R&D, making 12+ credits, possibly stealing some agendas...
In this example, without Pichação, clicks 5 and 6 don't exist before the corp can secure R&D. Pichação was worth 2 to 3 new R&D accesses and somewhere between 8 and 18 credits depending on how many trashables we found in R&D (and chose not to trash).
Even just a regular Asa list on Fully Operational is going to have some single-iced remote at some point in the game. If you can access that server cheaply and profit 3 to 4 credits per run, you can make 12+ credits in a turn, with Pichação being responsible for roughly half of it. There is even the option of simply throwing two Kyuban and a Pichação on a single cheap-to-break or unrezzed outermost ICE and jacking out after passing it, but this carries the flaw in that the corp almost certainly will trash that ICE next turn if they have another in hand to get rid of two Kyubans.
This card should cause absolute terror for any corp that sees it appear on the table at the right time, because it usually means the Shaper has achieved their Shaper dreams this turn, and your server is about to be their little playground.