Before revision:  On the contrary, such problems have been pivotal in obtaining completeness results for PPAD and PPA, for several important problems, such as finding a Nash equilibrium [Daskalakis et al., 2009, Chen et al., 2009b] and  Necklace Splitting with 2 thieves [Filos-Ratsikas and Goldberg, 2019].
After revision:  On the contrary, such problems have been pivotal in obtaining completeness results for PPAD and PPA, such as the PPAD-completeness of finding a Nash equilibrium [Daskalakis et al., 2009, Chen et al., 2009b] and Necklace Splitting with 2 thieves [Filos-Ratsikas and Goldberg, 2019].