I hate the fact that the US Big 3 fly ERJs even between their own megahubs. The number of frequencies is unncessary, wasteful and pollutive. If I were the regulator, I would ask them to run at least 2 widebodies a day with the threat of reallocating a few of their slot pairs to other airlines, hence reducing slot congestion, gate shortage as well as pollution. In China, the airlines together mitigate slot congestion and gate shortage by running some widebodies on domestic trunk routes without being asked.