But, for once more, you use numbers that aren't backed by facts. Paying 100,000 for an on-chain transaction is already untenable, and such transaction would be considered overspent in fees. Such fee would make some sense if all the billion users tried to open a channel within October.

Besides that, Lightning cannot cover a billion users alone. The simple answer is that if there's demand for something, it will be supplied. See Lightning. Before 2017, people paid nickles in fees, but an abrupt rise in median fee incentivized some hobbyists to take it one step further. Currently, fees are also nickles. Precisely, and at the time speaking, it costs less than 5 cents to have your transaction confirmed with low priority.