Edit Page button is gone

Check under settings -> reading and select the page where you want to show your blog posts. Then this becomes your blog page. You can set it to the home page or choose a static page for your home page.

See more info here: https://wordpress.org/documentation/article/settings-reading-screen/

You usually can’t change the layout/content of the blog page by editing the page in the backend. You’ll need to check your theme documentation for guidance on how to change the look of your blog page.