This arXiv preprint (v1, May 2026) uses full-f gyrokinetic simulations of edge and scrape-off-layer turbulence in ASDEX Upgrade to demonstrate that turbulence-driven poloidal flows create a deeper radial electric field well in favorable drift configurations via enhanced nonlinear energy transfer. The result is stronger flow shear that suppresses turbulence, lowering the power threshold for H-mode access compared to unfavorable setups. Unlike prior experimental correlations linking drifts to Er wells, this work supplies the first self-consistent mechanism rooted in turbulence-mean flow dynamics. Original coverage often frames H-mode news as incremental reactor milestones while overlooking how drift geometry fundamentally alters confinement regimes essential for net-gain fusion. Related studies, including Ryter et al. (Nuclear Fusion, 2014) on ASDEX Upgrade power thresholds and Connor et al. (Plasma Physics and Controlled Fusion, 2020) on edge turbulence scaling, show consistent experimental patterns but lack this first-principles closure. Limitations include the simulation's focus on one device, sensitivity to kinetic assumptions, and absence of peer review or multi-machine validation, leaving open questions about extrapolation to ITER-scale plasmas where steady-state operation demands minimal auxiliary power.