Earlier quoted context omitted.
There is some etiquette involved. You don't want to be the first person there, just as you should avoid being the 'lingerer' who stays too long or even worse needs to be asked to leave explicitly.
Why don't you want to be the first person? I've heard of "fashionably late", never anything about "early". IME early bird gets all the good nachos. And you can leave earlier.
In some cultures appearing a busy person can be important. Showing early to a party could send the message you had nothing to do before. Not that i like or do that, but some people could pay attention to such details.