so for an example.
/blog/2019/02/02/how-to-secure-a-ubuntu-linux-server-in-3-simple-steps/
redirects to
/blog/how-to-secure-a-ubuntu-linux-server-in-3-simple-steps/
That is probably because of the trailing slash. You might need another page rule but I cant guarantee that you will get this to work. Server-side is probably still the best choice.
You can try Redirection, an excellent free plugin with which you can set your regular expression redirects. It allows you to write redirects to your .htaccess file.
The formula /*/*/*/*/, even if it worked with or without the trailing slash, could be problematic, as WordPress generates all kinds of archive and paginated pages that might result in something like:
example.com/category/category-name/page/3/ being redirected to example.com/3/ and that would be a 404!