but personally, saying

I don't understand why it matters how you say the date vs. how it's written with slashes.

If someone asks you the time, and you look at your watch and it says 11:45, you could just answer "eleven forty five", but depending on the context you might just say "It's noon" or "It's almost noon" or "It's a quarter to noon". 11:45 is how you get the information into your brain. How you process that information and how you pass it on depends on the context.

The best date format is clearly ISO-8601, YYYY-MM-DD. In that format, US independence day is 1776-07-04. But, you don't need to say it as "seventeen seventy six, seventh month, fourth day". You can say "July 4th, 1776" or "The 4th of July, 1776".