While I love decentralization progress, the great majority of end-users look for UX don't matter what is behind. They don't care if it is decentralized, federated, or centralized. Git is decentralized but most people use GitHub and the UI cannot be decentralized. Also there is a lot of irony here where most decentralized projects use Slack or Telegram for messaging.
I looked into Secure Scuttlebutt community, and while I didn't muster up the courage to really participate, I kinda like that they take dogfooding seriously.
Their protocol started as a secure peer-to-peer log-store, with first application as a white-list based social-network [1]
The more interesting part is a git plugin that allows to store repositories in the distributed log as well. This is complete with a nice web-UI and some rudimentary issue management [2]
If you had right group of people, you could use this on a local-network, with no internet access, and you'd have reasonably nice environment for chatting and collaborating :-) In practice you'd want to be on the internet and connected to at least one scuttlebut pub to actually see other people, unless you really organized some sort of offline-cabin-retreat-hackathon :-)
That's why it's important for us who are working on decentralized projects to not use "decentralized" itself as a feature but rather use the side-effects of what decentralized technology brings.
The first ones that comes to mind is:
offline-first, local-second and internet-third. Basically, the applications you use day-to-day should work no matter how you are connected. If you are on a local lan, the application should work with the rest of the clients who are on the local lan. Slack would be amazing if when it looses internet connectivity, it simply tries to connect directly to other clients around it.
Performance. Decentralized applications can be much faster than centralized ones, for the majority of the people on the internet. If I'm in South Africa and using a web application with it's servers in US, there is a maximum speed the application can work at, no matter if I'm working with someone next to me, or in China. With decentralization, we can move logic closer to the people needing it.
Security. Less important for the average person but more and more people are caring about it. Apple seems to have a focus on it that actually makes security-conscious people chose them for it. Not having everything going through the same centralized service makes that centralized service less of a target, and decentralized technology usually does a way better job on using encrypted communication because it's needed when you send data peer-to-peer.
If instead of applications writing "It's decentralized!" on their landing pages like that's actually a feature, they explain the benefits of decentralization, I think it becomes a lot more interesting for the average person.
Totally with you on the disappointed part. People want things to work, but they don't care why something works and something else doesn't. So usually they allow others to bullshit them into using mediocre solutions just because these were cheaper to implement for the "provider".
However decentralized systems have huge advantages. E.g. in an unsure system (i.e. the normal broken unreliable network, especially when on mobile) decentralization helps to keep the few things running that by coincidence currently work. In a centralized system you always have a few things that really, really need to run, otherwise nothing works. That's for instance why the "ugly" email has survived the competition against "userfriendly" chat apps like ICQ and QQ. People still use email today. So even without much interest in them there can be quite some value for people who implement and design them.
On mobile, offline first products simply work better and provide a better user experience. That doesn't require decentralization, and there are some apps were it won't be useful.
