Equal: regarding or affecting all objects in the same way.
Fair: marked by impartiality and honesty : free from self-interest, prejudice, or favoritism.
Pretty close synonyms right?
To treat people equally doesn’t mean you’re treating them fairly. You can treat people horribly and as long as you’re consistent, that’s equality.
Fairness therefore, is a better goal, especially when some laws we have and themselves unfair.