I think it has a chance at becoming a settlement layer or store of value, so will be a digital store of value rather than digital cash. I think something like NEM or Ripple is best placed for the digital cash front. Bitcoin has the advantage that it was the first.
I agree with your statements(hence why I gave you a merit), except this part. I really don't know about NEM, but XRP is simply too centralized to be a method-of-payment coin. Like, it has a CEO, might as well use a debit card instead, or better, physical cash for better anonymity.
I'm personally still betting on the lightning network for the future. If it "fails", then there will likely be more solutions. It's pretty much just a matter of when. The altcoins we have right now that are aiming to be for-payments, are mostly just speed. I personally think security and decentralization is still far more important than speed.