Like others said, you can discuss all you want about the technical aspects of a new coin, but the main an most important issue remains and it's an old one. To make actual people using it and go full mainstream. Security is even something minor in priority, there is credit card and bank fraud everyday with the actual system.
This is similar to what happens with the PC and MAC if you want. We all know Wozniak and others invented the technology but as amazing as it was, it needed a visionary to bring it to the masses. For that to happen, you need to make deals with Google, Amazon, Microsoft, Facebook and Apple. People will embrace Bitcoin or whatever cryptocoin they implement, that's it. Or they will create their own, which is most likely and that will be the one.
Bitcoin is like Napster if you want, Apple or a company like that will see the potential when it fits and create iTunes. But that took A LOT of impossible deals with the labels music industry moguls.
Somewhat reasonable analogy but as I recall Napster got literally nowhere where with big companies, and there certainly was not an entire nascent industry of VC-funded companies building around the Naptser ecosystem, whereas Bitcoin at least has some support from large companies (for example you mentioned Microsoft, which
accepts Bitcoin) and many startups are building on Bitcoin, and this can really only be said to a significant extent for Bitcoin specifically (i.e. see above "to scale" list). Whether that is enough to not get replaced by iTunesCoin is hard to say, but the differences with the Napster experience are certainly there.
I understand the comparison is not perfect nor fair. However Napster had the piracy issue, their reputation was tainted. Bitcoin also has this to a much lesser extent, but really the average person doesn't care that it's "anonymous" or decentralized, for god's sake, they use Google and Facebook all the time.
It just need to be somewhat secure, cheaper and easy to use. Bitcoin and others already have these features. To me it is inevitable that a major player will come out with it's own coin/currency and the rest are doomed.
It can be sort of a subscription and small limit plan too, kinda like store credit but that can be accepted and used in many places. If you have some extra iCoins, you can pay Spotify with that or renew a Netflix subscription.
Well look I think the existing payment methods are somewhat secure, cheap, and easy to use. Netflix, Spotify, etc. have how many subscribers? Amazon has how many customers? Somehow these people are getting along fine without Bitcoin. They don't miss it at all.
That's not even true for Napster. Napster had far more pull demand from (most) users than Bitcoin/crypto ever has, the latter being more of a solution in search of a problem. Exceptions maybe being things like online gambling (including coin speculation as a sort of gambling game) and online drugs.
There is a context here. When satoshi built and released Bitcoin it was in the wake of the 2007-2008 financial crisis and there really was a desire for something better. Outrage over bailouts, Wall Street bonuses, etc. was mainstream. Strong hatred of banks and bankers was common. Even many in the power elite were open to alternatives. There really was a sincere and widely-held feeling that the system was broken. That was nearly a decade ago and much of that is gone. There are some low-level concerns, but the average Joe no longer gives a shit about banking one way or another. Politicians no longer mention it. The problem that Bitcoin was largely intended to solve no longer exists from the perspective of people who would need to adopt it.
If and when the pendulum swings back, then crypto will have a chance to actually do something useful. Until then, Bitcoin is languishing and all the rest have no chance at all, outside of the speculation game.