- There are much better way to target multiple platforms while sharing code: Xamarin, React Native etc. (and not so good ones like QT/Swing and the like, I guess) - Apps made this way are not native to any of the platorms they run on - best case scenario they replicate platform UI and conventions poorly and with great effort, worst case they look nothing like native apps. Not as bad as Java does but close - HTML/CSS was never meant to be used to create UIs, they are meant to describe and style (hyper)text. It's a necessary evil when targeting browsers where there's no alternative, masochism otherwise - They are also slower and (much) more memory hungry than native apps - Slack happily eats 300+ megs of ram to do very little - They mean having to use JavaScript, instead of a better language with better tooling support - Many/most of the time the use case can be served by an actual web site/app - if you are making something that needs to connect to a database on a remote server to be of any use, why are you making an app to begin with?

Given the above downsides, why are Electron and the like so popular these days?