And we forgot to consider the full resources needed by banks. Yes, banks handle more transactions than Bitcoin, but banks don't only use energy/computer power for its transactions, what about the storages needed, what about the indirect expenses. While your bankster sit down on his chair he does not pedal to produce energy, his office uses energy too, when he goes to toilets he uses energy too, the transport of money, paying the employees, emails sent, letters sent, and so, are something to take in consideration
And at this point, you would have to add also the power consumption done by exchanges, online wallets, payment gateways ASIC manufacturers, nodes,
And to make things fair...we should take out from the bank's consumption the amount of energy wasted by people doing bank transfers to buy and sell coins, right?
And if LN allows to scale transactions, it may surpass all centralized payment networks. I haven't done the math for this, but intuitively I think would be cheaper compared to all the electricity banks and so on are using. Just imagine the amount of electricity one of these huge buildings consume.
We still have empty blocks...LN is needed only if we experience again an increase in transactions...
But it's been 8 months since the spam attack and the network has not experienced a single day of clogging.
And...the hashrate has doubled since April:P