If you have a workload that pushes the 13700K and 13900K to their turbo limits (and have ensured that those limits are actually configured to be the same), then

If you have a workload that pushes the 13700K and 13900K to their turbo limits (and have ensured that those limits are actually configured to be the same), then you really will find the 13900K getting more work done for the same power and energy. That's how the extra cores help in power-limited scenarios.