This sometimes happens, but it’s not what you WANT to be happening. Criminals in particular can cash up pretty hard with a combination of Testing and Siphon, but Anarchs and Shapers still need to work for their money against you.
What little ICE you play is usually taxing for the most part, (I am currently playing a mix of Yagura, Pup, Enigma, Komainu, and Eli). If you place this ICE well, you can often become a pretty taxing deck, (I usually try to ICE R&D with 1-2 pieces, HQ with 1, and the rest on a remote). If the runner has to get money, that’s time they’re spending not drawing cards and running. Are people playing Gambles against you? If so, MRF just saved them a click to draw a card and a click to play the card. That’s a pretty big deal. You want to be installing things fast enough that they don’t have infinite money, and thus have to make a choice between installing things and gaining money and actually checking some/all of your installs. There is maybe a version of PE that actually doesn’t care how much money the corp has. Such a deck would play less taxing ICE, (no pup, less Elis, more Bako/Enigma/Komainu, maybe very little ICE at all), but cambridge is not that version.