The baryon-to-photon ratio eta, equivalently the baryon loading R_b near 0.26, is the most consequential pure number in early-universe physics: it sets the primordial abundances, the acoustic peak structure, and the matter budget, and ΛCDM cannot compute it. The value eta = 6.1 x 10^-10 enters the standard model as a measured input, its origin delegated to baryogenesis mechanisms (electroweak, leptogenesis, Affleck-Dine) that each require beyond-Standard-Model physics, none of which has laboratory support, and all of which contain enough parameter freedom to accommodate any measured value: the number that anchors cosmology is, in the standard account, an accident of unknown physics with no derivation and no predicted value.
The structural embarrassment sharpens at the precision frontier: eta is now measured to a third of a percent through the CMB, the abundances confirm it independently, and the deepest available explanation remains "some asymmetry-generating mechanism produced approximately this." A framework able to derive the number from structure rather than fit it would convert cosmology's most precisely measured free parameter into its sharpest test; within ΛCDM no such derivation is on offer, and the baryogenesis literature optimizes mechanisms to be viable rather than predictive.
The standing is permanent within the standard model: eta will be measured ever better and explained no better, because the explanation lives outside the model's reach by construction. Any independent derivation, from any framework, faces an unforgiving comparison at the 0.3 percent level.