I have an iPhone 5s which I use daily…Now how is iOS 11 crap on this device? It runs fine for me and after restoring the system to factory settings it runs even better.
Truth be told I use my phone for calling, WhatsApp, Skype and a little bit of browsing. It works fine for me. It runs way better than iOS 9 on iPhone 4s and way better than iOS 7 on iPhone 4.
You can hope all that you won't but I don't think they will. I think iOS 13 will be the last release to support iPhone 5s.
If the rumours are true and iOS 12 will be a fix for iOS 11 then iOS 12 will run on the iPhone 5s. I trust EverythingApplePro on such things as he has always been correct so far.
You are making your own predictions and hoping… I think iOS 12 will run on iPhone 5s for sure. It's not slow enough.
We will see soon, but it's fun to read how people have always predicted phones and Macs get left out. Like when Yosemite came out people assumed that many Macs will be unsupported etc, yet older Macs were still supported.