The difference as I see it is that there will be little barrier to anyone setting up a hub. All these hubs will be interlinked with channels between them so you can set up a channel to any one of them and still have access to the whole network. That level of competition is going to have a significant impact on what level of fees anyone is able to charge.
to be hub you need to have connected to many channels.
this means depositing funds into MANY addresses to open such channels and have enough funds to act as a provider(hubs are for rich guys)
also to be a successful hub you need to be listed as part of LN's DNS seed (routing table).
..
that said we both agree its not a replacement for bitcoin. its just a third party service. thus does not actually alleviate bitcoins situation. infact when a hub needs to close its channels, it will be a blanket bomb effect because to ensure the hubs many channels tally onchain. it will ned to close them all simultaneously and with a large enough onchain fee for each of those tx's to ensure block acceptance
think of it this way. at the moment the blocks can only handle around 2500 tx's. which means when its time to close a hubs channels. that hub better not have connections to more than 2500 customers, otherwise there will be a bottleneck.
and yes hubs will need to close channels because funds will need to move. to refill the channels
EG
if A connects to B which connects to C
if A wants to use B as the hub to pay C for a coffe each day
A+B have a channel and both fund it
B+C have a channel and both fund it
so day 1
channel1 | channel2
A:0.001 | B:0.001
B:0.001 | C:0.001
so day 2 - a pays b in channel 1 .. and then B separately uses B's channel2 funds to pay C.. the funds of channel 1 dont physically touch C. its B that does the borrowing for A
channel1 | channel2
A:0.0009 | B:0.0009
B:0.0011 | C:0.0011
so day 10 - a pays b in channel 1 .. and then B separately uses B's channel2 funds to pay C.. the funds of channel 1 dont physically touch C. its B that does the borrowing for A
channel1 | channel2
A:0.0000 | B:0.0000
B:0.002 | C:0.002
A in channel one has nothing left.
B in channel two has nothing left. thus B will need to close channels to settle up
now imagine it if B was paypal with thousands of customers not just 2
stil unsure about the need to close channels.
imagine you had a $30 walmart giftcard.
your wife gives you $10 CASH and says she wants to buy stuff at walmart with your giftcard.
your wife the next week gives you another $10 cash, same again
your wife cannot just keep handing you $10 forever and just use the walmart card. at som point you will have $30 CASH in one hand and a walmart card of $0 balance so you will need to refill the giftcard with the cash. which involves closing and reopening channels