get_post_type_archive_link(‘post’) returns current category archive

get_post_type_archive_link() doesn’t return a link for the post type post, because technically it has no archive registered on registration of the post type. You can check this, if you inspect the output of get_post_type_object( 'post' ). So actually get_post_type_archive_link( 'post' ) will return false – see source.

You can get the link for the page for the posts another way:

$permalink = get_permalink( get_option( 'page_for_posts' ) );