The story of universal suffrage isn't that clear cut.
To this day, we generally don't allow people to vote in an election if they aren't a citizen yet I reckon we don't consider non-citizens lesser human beings. The idea of allowing only those with property to vote (because they have stake in the country) or to only allow men (they will be fighting the wars) are outdated, but they aren't nonsensical.
It wasn't really that long ago that all/most societies believed that slavery was normal.
Just the IDEA that "all men are created equal" is intensely liberal. And that it was put into a document without qualifiers is miraculous. We can't judge the past only from a modern lens. YOU didn't do anything to help the world move towards liberal values. YOU are just the benefactor of thousands of years of conflict/learning/etc.
Man as in mankind. https://www.merriam-webster.com/dictionary/man
>1a(1): an individual human
>b: the human race : HUMANKIND
>c: a bipedal primate mammal (Homo sapiens) that is anatomically related to the great apes but distinguished especially by notable development of the brain with a resultant capacity for articulate (see ARTICULATE entry 1 sense 1a) speech and abstract reasoning, and is the sole living representative of the hominid family
I argue that it hasn't; we say "man" both by itself and as part of another word (eg: manpower) in many contexts where gender is literally irrelevant.
What has changed is the likelihood of certain individuals engaging in sexism in the name of equality.
-Jean-Luc Picard
Additionally, the Declaration of Independence states our fundamental philosophy as a nation that all men are created equal. We all start from the same line, but where life takes us and what we make of it is completely up to life and us the individual.