applications have disappeared from the finder applications folder, but still appear in the launchpad and in the applications folder of the dock

Your screenshot shows that there is a huge scroll view below what you are showing. Have you scrolled to the bottom/right.

Based on the two windows shown, you have the scroll thumb set to relative size of what you are viewing, so the tiny thumb on your Applications folder shows that there is a lot of content below and to the right of what is shown.

You can also use the View Menu to Clean Up by... Name (or whatever). That should move all of the icons into the width of the window.