"theoretical physics" is such a big and ambiguous concept that physicists tend not to use the word in discussions. Thereotical work often involves a lot of numerical simulation on super computers these days which are kind of their own "experiments". And it is usually more productive to just mention the specific field, e.g. astronomy, condensed matter, AMO etc, and you can be sure there is always a lot of discoveries in each area.
Physics is not stuck in string theory as physics is not just high energy theoretical particle physics. There's also more going on in high energy theoretical particle physics than just "string theory".
Much of the experimental action in recent decades has been in low energy theoretical particle physics. Down near absolute zero, where quantum effects dominate and many of the stranger predictions of quantum mechanics can be observed directly. The Nobel Prizes in physics for 1996, 1997, 1998, 2001, and 2003 were all based on experimental work down near absolute zero.
