Counter counterpoint: Often frontend js code is minified so that it is smaller and more efficient to transfer to the browser. For FOSS projects you should still be able to get access to that code, unminified, from the project git repo. In the same way desktop apps often ship as binary executables but you can still see the code that was compiled to build them if you find the source repo.

It does make things harder to debug for an average user but it makes it faster/more efficient to run for most end users (in the case of the desktop or phone app it makes it possible to run without needing compiler toolchains that mom and pop likely wouldn't be able to grasp).

The key thing isn't that what the end user's computer runs is readable and editable but whether the code used to build that artifact is available easily and what restrictions there are on editing and redistributing that code.