Cancer isn't one disease. Targeted treatments take a long time to develop, and only cure one type. The vast majority of cancers are still treated using a sledgehammer approach. I had lymphoma, and took both a general poison (bendamustine) and a very narrowly targeted monoclonal antibody (rituximab). The bendamustine kicked my ass a bit because it's simply poison. The rituximab hardly had any side effects at all, because it only targeted specific cell types (both healthy and cancerous cells of that type, but still focused).

The idea that there is or ever will be a "cancer cure" is a popular misconception. There are hundreds--if not thousands--of cancer variants. The more targeted the treatments are, the fewer patients any one treatment can help. It takes a decade or more and hundreds of millions of dollars for each targeted treatment. There's still an enormous need for broad-spectrum treatments in addition to targeted ones.