ELI5: What happened to needing "www" in front of an address?

Explaining like If you were 5:

You know when you send a package in the mail, you write the address and maybe, If the package is “Fragile” you’ll stamp “FRAGILE” all over it.
Why don’t you also stamp “NOT FRAGILE” on the packages that are not fragile? Because It’s implicit. If you don’t say anything the mailman knows It’s not fragile.

Same thing goes for the WWW. Since you can have multiple services on your domain (ex: ftp .address. com which means you want to share files; or mail. address. com which means you want to access the mail server on that domain) in the beginning you’d also write “WWW. address. com” to state that you wanted to access the HTML of the server.

As the web evolved and 99% of the average user wants to access the HTML version of the website, website owners no longer require you to type “WWW. address. com” instead, If you type “address. com” they assume you want to access the HTML version.

Just like you don’t need to stamp “NON FRAGILE” on your package, you don’t need to type “WWW”. Everyone assumes that’s what you want If you say nothing otherwise.

Explain Like I`m Five: good questions, best answers.