Yes, When US roaming doesn't work well, that's the time I will certainly get a local sim card, but since I have Google Fi I haven't have the need for it. I used Tmobile with free international roaming feature before and it was fine too. I bought foreign/local sim card before and it was fine. Now I have Google Fi and am satisfied with it, based on my travel patterns in Europe, Latin America, and Asia. I only travel to metropolitan areas, and I often stay in countries for short periods of time, and just hop around.
My complaint was about LINE, not my phone carrier.