I guess to answer the GQ, it is because some things in your code and long pieces of script
will not amuse the viewer, especially if they have no idea what they are looking at. Which is
why hiding the things that are necessary for the web page to work is useful. Most likely it
will make your web page look nicer without all the codes show up.
to add on, Meta data and all the meta tags are needed because it tells the browser
how to display the content. for example it tells you what language and adds key words such as
html and school will let the web page when those words are searched for.