Evaluate competing microscopic mechanisms proposed for high-temperature superconductivity in cuprates. Assess theoretical foundations (e.g., spin-fluctuation–mediated d-wave pairing, RVB/Mott-correlated scenarios, stripe/nematic order, and electron-phonon contributions), compare their predictions for pairing symmetry, gap structure, the pseudogap and normal-state anomalies, and critique how key experiments (ARPES, neutron scattering, STM, NMR, transport, isotope effect) support or contradict each; propose decisive experiments or analyses to discriminate models.