Is it too late to train foot work when you’re over 30 yrs old?

Isn’t stepping back foot first before stepping front foot when moving backwards boxing 101? Why can’t Wilder do this and he keeps moving front foot first and crossing legs when moving backward from pressure? Is he too old now to learn basic boxing foot work? Don’t even amateur coaches teach this when you take any boxing class? Why wouldn’t his coaches at this level of boxing tell him this like 10 years ago?