Lightning offers more private transactions than any other insurance payment method and does so without introducing debt.
In order for it to become widespread, it needs to meet the global market demand and, unfortunately, the global market wants dollars. Tether's success tells us that the global market is willing to accept dollar substitutes.
There are several ways that this can happen including Dollar Exchange, Dollar e-cash, Taproot Assets, Stable Channels, and Stable Sats.
With the available tech everyone can escape their currency and choose another, they will choose the better money available, people suffering from high inflation will choose usd bc it's a massive improvement for them and can trade globally, see Argentina, aftwards they will start saving in BTC. In the long run the world will be on usd and btc only, and btc will win.