A decompiler extracts resources (images, sounds, scripts) from the SWF and converts it into a readable format.
If you don't need to re-design the whole file and just want to change a graphic, a link, or a text string, you might not need to export to FLA.
Some SWF files were compiled with "Protect from Import" flags. While most modern decompilers can bypass this, it indicates the original author did not want the file edited.
If you have the original source files, Adobe Animate is the native environment for these files.
This is perfect for simple tasks like updating a copyright year or swapping a logo without risking breaking the complex ActionScript code.