Perhaps you are interpreting their request to not use username and site name and instead use email, to instead use a long form Lemmy username?
No, I was saying to use their Fediverse username and their Fediverse password. Sorry if I got misunderstood. Nothing to do with the actual email address used at signup.
To do so, there would need to be a centralized or federated list of all accounts
Why would there be? The app would just search for the domain name first (let's say "aussie.zone") and then your username (in your case "hitmyspot"). That's kinda how email works as well. What centralized database would you need to interrogate a server on login? It's no different than the current implementation, only that you do not need to remember the website first, just enter the whole username in one go.
This looks rather like a discovery issue and is quite common with newly created instances on the Fediverse. You have to search for everything you want for a couple of times before you make your instance aware of the content or other instances aware of yours.
You can more easily overcome this by connecting your instance to an ActivityPub Relay, but I don't know how this is done on a Kbin instance.
I was a RedReader user for quite a while (as in years). While being a bit spartan, I found it to be the best Reddit app for my preferences. Period.
But indeed, nowadays, there is actual (great) content on Lemmy and Kbin, and I am willing to get to it. Not much time left for Reddit. Sorry, spez, fuck you!
I don't think it's a case of a personal ego here. I think it's something different, that has to go with the main devs' ideology. I feel like @feditips 's concerns are quite valid.