Yeah but the problem is much less with the scalability of LN itself but the on- & off ramps TO lightning.

If we assume roughly 5000tx per block we arrive at around 260'000'000 transactions per year.

If we say that each person would make just two off-chain transactions per year (one in, one out of coldstorage) then we could only sustain 130 million people. That fully neglects any other on-chain transaction and transactions needed to run LN (opening, closing, rebalancing).