Uhmm, he’s working on quantum gravity too. Just a different approach. The same applies to loop quantum gravity.
> A practical implication is that it doesn't lead to any technology.
Who cares? It’s science not engineering.
> Smolin also doesn't like many-worlds, because it talks about unreachable regions. This he considers too speculative. There's a basic problem in quantum mechanics, which leads to Schroedinger's Cat, the Copenhagen Interpretation, and, in the end, many-worlds.
The string landscape [1] and the many-worlds interpretation [2] are two completely different things. The string landscape indicates that string theory may never be able to make any predictions. Some physicist try to use many universe in combination with the antropic principle to “solve” this problem. But I’m pretty sure this is a very small minority.
The many-worlds interpretation of quantum mechanics is just that, an interpretation. It doesn’t make any measurable difference from any other interpretation. And the Copenhagen interpretation doesn’t lead to many-worlds, they are just two different interpretations of the same theory.
> Physics has been stuck on this problem for almost a century now.
At this time I wouldn’t call it a “problem” of physics. If all predictions are the same it’s just a matter of taste which interpretation you prefer. To bring it into the realm of physics you would need to come up with some kind of theory of the measurement process that actually makes testable predictions.
[1] https://en.wikipedia.org/wiki/String_theory_landscape
[2] https://en.wikipedia.org/wiki/Many-worlds_interpretation