Agile/Waterfall (there other options, too) dichotomy is not just about developing or testing a product, but also about organizational culture. In general, I don’t believe in “scaling Agile” too much (we don’t even see Agile adoptions, in general, go that swell), but e.g. Nexus, SAFe, and LeSS aim to address this. Here’s one opinion how Agile “techniques” could help mitigate the risk of cost overruns for enterprise software development.
About can Waterfall do the trick… well it has “worked” as it has for years. The successes and failures from those experiences are good data to look at. Of course we can do better, but every ship sails like the captain tells. 🙂