The standard ΛΛCDM cosmology relies on phenomenological assumptions of dark matter and dark energy to fit observational data, yet fails to reveal their physical nature. Based on the XLG Eccentric Collision Cosmology (ECC), this paper abandons the ad-hoc parameters of dark matter and dark energy, takes the eccentricity ε=1/137ε=1/137 as the first principle, and establishes a new cosmic dynamics framework centered on the KuiQuark Sea, blocking effect, and repulsion gravity. By piecewise parameterizing the expansion history H(z)H(z), deriving the gravitational wave dispersion relation in the KuiQuark Sea, and numerically solving the structure growth factor D(z)D(z) without dark matter, this work systematically verifies the self-consistency and observational compatibility of XLG cosmology. The results show that the XLG model deviates from ΛΛCDM by less than 1%1% in the BBN era (z>6000z>6000), satisfying early universe constraints; the Hubble rate increases by about 10%10% in the transition period 3000<z<60003000<z<6000; the gravitational wave dispersion is <10−15<10−15 in the LIGO band and becomes cumulatively detectable in space detector bands; the structure growth factor is consistently lower than that of ΛΛCDM, and the error band of η0=0.12±0.03η0=0.12±0.03 covers the observational data. XLG cosmology completely abandons dark matter and dark energy, self-consistently explaining expansion, gravitational waves, and structure growth, with ΛΛCDM being its low-redshift steady-state effective approximation. Three testable predictions are proposed for verification by next-generation CMB, space gravitational wave, and survey experiments.