While I agree that only increasing block size forever (or simply removing the size limit) doesn't seem reasonable in the long run, are we sure that segwit and the off-chain scaling solutions proposed today will really solve the long-term scaling issues of BTC?
All the practical "here's how lightning's going to work" papers I've read so far leave me very skeptical. Here's an example: http://diyhpl.us/wiki/transcripts/scalingbitcoin/hong-kong/o...
The Q-and-A at the end in particular is interesting:
>Q: On the last slide, one of the assumptions was 3 channels per person. Assuming payment channels wouldn't be useful for retail sales, because you don't want to buy a coffee just to open immediately. Is that correct?
>A: Joseph might expand on this. Let's say you buy a coffee. You're probably buying a coffee only once, right? Well, maybe the coffee is $5, and you put $50 into the channel and leave it open. Then someone else comes to the coffee shop and she does the same thing. But she has a channel with the grocery store. There's me, coffee shop, Alice, grocery store, they all have channels. When I go to the grocery store next time, I don't have to open a channel. Payments are routed.
>Q: It sounded like everybody would have to open new channels.
>A: I am guessing the mean is going to be 3, but it will probably be an exponential distribution. Most people will probably have 1 channel, and then some might have 100s of channels open.
I don't know about you but while on paper that might work I still see a lot of hand waving, guesswork and rather unsubstantiated assumptions. Why would I decide to "lock" $50 worth of Bitcoins when I buy a $5 coffee? What's the incentive for me to do this? Where does this estimate of 3 come from exactly, I see it repeated everywhere but I can't find the maths behind it?
Here's an interesting attempt at simulating a real-scale ligtning network (why aren't there more of these? Aren't we talking about a $40bn market cap currency here?): https://hackernoon.com/simulating-a-decentralized-lightning-...
The simulation is rather unrealistic and I'm not sure how to interpret its conclusions. It seems to kinda work but there are issues:
>133,401 micropayments were attempted and 3461 (2.6%) of these failed. For successful payments the median number of hops was 19 and the median total fees were 2 bits (0.000002 btc) or 32% of the value transferred.
Now it could be caused by a bad simulation rather than a real issue with Lightning network, but frankly I can't tell at this point.
I don't have a horse in this race but as seen from the outside it all looks a bit rushed and amateurish. I don't know the whole story though, maybe I'm just poorly informed.