That's because of the nature of the Lightning Network. You can only see transactions going through your own LN node, if you run one. Only the opened LN channels are visible for everyone.

Sure. But the amount of channels gives an indication on the potential users. And it's way way less than on the main network, basically a footnote at this point.

Yeah it _might_ grow in the future. But until it does it doesn't work as an argument.

Also in order to get into Visa levels of efficiency one would have to have (assuming the 741kWh in the main network) 500k TX per second in the lightning network with 0 energy cost. Visa handles around 1700 per second.

So basically if we'd have all the worlds economy in Lightning network we might get close to those numbers (assuming 8 billion people each doing one transaction per 4 hours, that's super high but ah well, whatever). And that's assuming the mining energy consumption doesn't change at all which it definitely would not do in case of the whole world relying on Bitcoin.

The amount of channels doesn't give any indication on the potential users. For example a bitcoin exchange can have one LN channel open with the rest of the network and allow many transactions per second for all its users. And I believe LN will grow much bigger than VISA, because not only people will make transactions, also programs who will send many micro-transactions to eachother, something which is far from possible with the VISA network.

Ok, but according to that site, the total capacity of all those opened channels is only a little over 1,000 BTC. The whole BTC network spends about that much on mining (block rewards + fees) every day.

So is 1,000 BTC a lot of money, in which case, it's a lot to spend on mining?

Or is it a small amount of money, in which case, it looks like LN is hardly used?

You can have an LN channel worth 10 dollars of bitcoin left open for years, over which unlimited transactions route worth 10 dollars or less each.

Exactly - and I can say from experience that this does generally happen. I manage a node that receives significant amounts over lightning, and channels are typically reused with batch "loop out transactions" that free up liquidity by converting a bunch of lightning transactions into onchain funds without closing a channel.

The whole point of lightning network is to be p2p, so you're not supposed to know how big it is or how often it's used.