Single exes are nice, but people still don't want to download and run single exes. Once you use an installer or package manager to grab it anyway, doesn't the benefit become smaller?
I guess for some scenarios such as deploying webapps etc, it might be very handy to copy ONE file and run it. But for client apps, is there a visible improvement to having 1 exe instead of 1 exe and 5 dlls, which are the same size together?
I've written a few utilities that have been released to the public. In my eyes the most important aspect of a single executable is simplicity. I personally prefer applications that I can just drag to any folder. I think, even though I don't like the OS as a whole, macOS does a pretty good job at creating a compromise with .app folders. You can keep framework dependencies, embedded resources, etc contained within one area that you can move around easily, but you don't have to package it up in the binary.
I see the whole thing as more of an issue of your target demographic and the scale of your application. Things that run as background services would make sense to distribute as an installable package. Larger applications like Office or Visual Studio are much too large to throw in a single executable. Something else though like Acrobat Reader or FileZilla I think would make sense to distribute as a single executable. Most times I just don't want to install anything. I use FTP so seldomly that I'd rather want to just download a portable FTP client than keep something installed or even have to extract a multi-file archive somewhere.
I guess for some scenarios such as deploying webapps etc, it might be very handy to copy ONE file and run it. But for client apps, is there a visible improvement to having 1 exe instead of 1 exe and 5 dlls, which are the same size together?