The source for the quote in the title is the Lightning Network whitepaper, posted here (Warning, PDF!)

ok, so let's have some fun with math…

The current Network, with Segwit, will provide for the effective equivalent of ~2,000,000 bytes per block, or an average of ~4000 transactions per block (using 500kb per tx, per the LN whitepaper).

Let's divide 2,000,000 by 133,000,000 to apply the LN devs' math to the current solution. Answer:
0.0150375939849624

OK, now lets multiply 7,000,000,000 by that result to get the number of users who could do the same with just 2MB blocks. Answer:
105263157.8947368

So, using this math, we can see that ~105 Million people could each open (not close!) just 2 LN channels PER YEAR.

This also excludes all other uses for the blockspace!

So, now what? Where do we stand if LN does, in fact, become popular (or even hyper-popular)? How many years will it take for LN to fully saturate and overwhelm the current 1MB+SW solution? Is opening just 2 LN channels per user, per year, very realistic? If not, what is a more realistic value?

I'm not writing this to be hostile or take shots at the current plan, or the current devs — I do appreciate the fact that this is a VERY difficult problem, as well as the need to get it right.

Instead, I simply want to remind people that a hardfork is still eventually necessary, and to inspire some discussion on these very real concerns.

So, again, what are the options after SW and LN?

BU and EC are obviously not the answer — they're f'n terrible — so what's the latest and greatest for a viable hardfork that would allow for on-chain scaling well into the future? What are the latest ideas/concepts being discuss behind the scenes that may or may not have been shared on the mailing list and github yet?

I think it's clear that layer2 solutions will require additional blockspace well beyond what 1MB+SW currently provides, so please don't dismiss this issue outright. It's a hard problem, but it's still one I think we must solve long before the network gets overwhelmed by LN and others.

Please keep it civil… 😉