Run terribly everywhere, with lowest-common-denominator functionality.
I loathe this trend. With everything calling back to a backend in the sky anyway, it should be easier to make light, efficient native shells with good UIs.
Perhaps this is a matter of personal taste but I don't want cloud-backed apps, I won't use anything but 100%-local as long as I have choice.
I also don't want to invest time in developing anything that won't run on all the three major OSes (Mac, Linux and Windows) when built, nor to invest any serious additional effort to achieve this. Being able to run the app in a browser after minimal modification is a nice-to-have bonus (probably very important for many people who develop web-first).
As for now I use WinForms and Qt frameworks to achieve this but I probably am going to switch to Electron if Flutter Desktop doesn't get released soon.
Nevertheless, as a user I would indeed prefer native GUI desktop app talking to their web server for data over a web site.
Perhaps people would develop apps this way if there was a native GUI framework as powerful and easy as web frontend frameworks are and if there was a way to publish you apps a way people could discover and run them in a couple of clicks. Perhaps MS UWP with WPF and Windows Store could do the job much better than web apps but sadly it's not cross-platform.
I loathe this trend. With everything calling back to a backend in the sky anyway, it should be easier to make light, efficient native shells with good UIs.