This isn’t strictly a Pathfinder thing but I like this community.
Basically, there is this meme that Human Figher is a “boring” default choice or sign of an uncreative character. I disagree. Picking out a weird ancestry is not creative. Choosing a human fighter basically means that you get zero flavor from your ancestry and class - so you are forced to get creative yourself. You are forced to give your character a personality, and you are forced to solve problems creatively.
For me, the stereotype is the opposite - if a player chooses an esoteric ancestry and class combo, I worry that their characters whole personality is just their ancestry.
Of course both humans and other ancestries make for great characters if done right.
I think where I would disagree is in wording.
I think a human fighter allows nearly unlimited creativity, but doing so requires a player with imagination, and DM that’s open to them doing it. Truth is, a lot of players don’t want creative characters that make them really open up. They want at least some degree of comfort in their character. Tropes exist for a reason, in other words.
But, yeah, in any system I’ve ever seen, a standard human fighter tends to be the best blank slate for going all out with.