As shown in practice by adoption of credit cards and other financial products, people (well, most of them - the 'buyers') for most of their daily business do not want irrevocable transactions like bitcoin provides, but transactions that are reversible and can be controlled by legal authorities.
Because fraud matters. Because consumer protection for all kinds of non-delivery, mis-delivery or simple misunderstandings is actually more important for everyday purchases than all the advantages of an independent cryptocurrency. And of course, widespread availability, liquidity and value stability are just non-optional table stakes.
Bitcoin on its own is not competitive as a replacement for the full payment infrastructure. Bitcoin together with a widespread trusted escrow system, reputation system and a (currently unavailable) legal framework could fit the role, but in that "Bitcoin++" the missing parts are larger and more complex than the Bitcoin core implementation.
"In theory, this distributed micropayment network–the Lightning Network–could scale Bitcoin transactions up to “billions of transactions per day” across the planet, with minimal use of the blockchain and minimal fees (zero, for direct channels.)"
Instant and way more than 7 tps... Settled on the blockchain and still decentralized. ;)
Lightning Network has a number of problems as the solution for Bitcoin's problems:
2. It's a sidechain - that is to say, an altcoin that claims a link to Bitcoin. The forces that would cause mutually-distrusting individual humans to maintain the linkage is unclear.
1. Like other sidechains, but unlike altcoins, it ... doesn't exist. This is a subtle point, but I think it might be an important one.
(not that I am any fan of altcoins either. But basically, the Bitcoin protocol as it stands was never designed with scaling in mind.)
It's a new protocol that needs to be accepted on top of the blockchain with its own 3rd party sidechain, just like all the other proposed solutions that were never accepted by the community. Cool.
