It hasn’t produced the Landscape (the multiverse). In fact,

After 60 years, this beautiful theory hasn’t produced many tangible results…

The truth is, by and large most string theorists aren’t working on the whole unification thing anymore. Instead, what’s captured the interest of the community is an intriguing connection called the AdS/CFT correspondence. No, it’s not a new accounting technique, but a proposed relationship between a version of string theory living in a 5-dimensional universe with a negative cosmological constant, and a 4-dimensional conformal field theory on the boundary of that universe.

The end result of all that mass of jargon is that some thorny problems in physics can be treated with the mathematics developed in the decades of investigating string theory…

But if that’s all we get — approximations to what we hope is out there, a landscape of universes, and a toolset to solve a few problems — after decades of work on string theory, is it time to work on something else? There must be other ways of conjuring a multiverse.

Paul Sutter, “Is string theory worth it?” atSpace.com

At what point will people begin to wonder if this is really science?

*See also:* The multiverse is science’s assisted suicide