I guess the crux of the question is, where are we more likely to encounter new physics? The standard model already explains almost every experimental result, but not EVERY result. But what are some of the most important results that are either incompatible with the standard model or just inadequately explained? Usually when there were major breakthroughs in physics, you had a phenomenon or a class of phenomena that couldn't be explained by the old theory. For QM it was the ultraviolet catastrophe, the photoelectric effect etc, for example. Is there any chance at this point that the solution to the impasse physics kinda seems to be at could come in the form of an explanation of some yet unexplained effect?