Specifically: L2 like lightning, settlements on sidechains, and other things I won't go into here.
The long and short of it is that it's incredibly hard to quantify and compare and I am yet to see an attempt that gives any meaningful insight.
If Bitcoins proof-of-work and the consequences it has becomes a net loss or net win in terms of climate is a very open question. I would love to see more analysis of it but it's really not obvious either way.
Adoption has been extremely slow and the two main implementations (lnd and lightningd) are far from complete and feature-compatible, even if development velocity is actually very high in both.
There are serious efforts in development to improve on all the current problems, and relatively seamless interoperability and liquidity bridges with L2 networks on other chains like Ethereum is IMO the coming key to make it happen for real.
In practice it should not be necessary for a retail user to run or maintain their own always-on node(s) in order to get the benefits in a secure way - but much of the required plumbing is still in heavy development.
It's OK that it takes time. Maybe it's another 5-10 years until you will be able to appreciate it - I think it's shorter than that but time will tell.
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TLDR lightning hasn't fully arrived yet and it will continue to happen gradually
It doesn't matter how much is fixed or tweaked in the code, it won't help. We don't know how to solve routing in Lightning. It's just not a tractable problem.
That approach does not scale, at all. If Lightning were ever to grow beyond a toy network, it would completely collapse.
(It's not commonly recognized and impossible to talk about without any pointers as to where the problem should lie)
In practice this needn't be an issue:
* Most nodes will rebalance, open and closed channels based on neighbour uptime and reliability
* In practice the LN network is expected to have a little but of a hub-and-spokes topology. So in practice you will almost always have a couple of well-known highly connected peers along your route
So it's a fundamental issue that will become a reality in worst-case scenarios but something that can be mitigated.
As one of the comments noted, we're somehow able to do this for TCP and TOR.
You linking to the /btc subreddit makes me think nothing anyone says or any developments will ever convince you (correct me if I'm wrong). In that case, I think your efforts are better spent in focusing on bringing value to the efforts you do believe in rather than telling others they're bound to fail.
https://github.com/moneybutton/yours-channels/blob/master/do...
2nd layer solutions will scale Bitcoin transaction capacity in terms of transactions/s
Then there's the question of whether a deflationary currency can even work in the first place.
EDIT: according to a chart here [0], 1 "raw" Bitcoin transaction is equivalent to 400k Visa transactions. That's 5 orders of magnitude. Unless Lightning handles 99.999% of all Bitcoin transactions, the Bitcoin network will be unbelievably wasteful.
And if you make that comparison, how much energy is being used to run Fedwire? A few kilowatts maybe?
BTC is a cryptocurrency, but not equal to cryptocurrency for the sake of this discussion.
BTC is arguably not effective as an actual medium of exchange. Many BTC maximalists have retreated from the actual currency use case in favor of "store of value" arguments.