US carriers are doubling and tripling many of the cheapest non-stop fares in US

Any economists want to weigh in on whey we shouldn't just let some of them go bankrupt? Doubling and tripling fares? And American, which I usually fly, charging $15 for the first bag (and more I believe for the second)? Thanks, since business travelers don't need to check bags but the rest of us do. What's next, charging for the life vest? This is why I don't fly US carriers to go abroad, ever, and haven't for years. They got too cheap a long time ago, and their attitude only worsened as the cheapness increased. I just don't need to pay $1000 to have someone treat me like they're doing me a favor.