I'd have to have opened a grand total of one channel over the past four years, personally - I have a suspicion that most people do not regularly gain more incom

I'd have to have opened a grand total of one channel over the past four years, personally - I have a suspicion that most people do not regularly gain more income than they've ever had before, as they spend it at a broadly similar rate as they gain it. In addition to this, as I said, the fact that Lightning Network is a protocol that allows cross-blockchain transactions between any two chains supporting Lightning Network means that if, as you say, Bitcoin has severe problems, everyone will just jump ship to another currency, as there will be far fewer switching costs.