But when you share some HTML in practice, e.g. send a HTML game exported from Godot to a friend, they will need to unzip it and install a local web server to ac

But when you share some HTML in practice, e.g. send a HTML game exported from Godot to a friend, they will need to unzip it and install a local web server to actually play it with appropriate permissions. Whereas .swf files could be opened directly in the browser without any preparation steps. It was also possible to read metadata from .swf files (background color, canvas size, etc), which made it very simple to automatically embed Flash games on web pages with the correct layout. So there are a lot of small practical details that made .swf a very convenient format for sharing games and multimedia content.