Allowing foreign flag carriers to cherry pick domestic routes, where the choices are likely to be city pairs where there already are reasonable numbers of compeitors, isn't likely to benefit consumers much in terms of lower prices, but might hurt our legacy carriers and lead to higher prices elsewhere in the networks. It's unclear whether the entry of foreign carriers into a few domestic routes would lead to better service standards for USA based airlines.

One must remember that the foreign carriers operate in vastly different regularity and labor environments. When labor is very cheap and workers have few protections, it's easier for a carrier to "overstaff" with additional FAs, thus giving the impression fo better service. It's even more unfair when the foreign carriers are permitted to discriminate on the basis of age, marital status, attractiveness, and other attributes that aren't related to job performance.