Of course looks is to a certain extent a birth lottery: as much as I would try, I could not change my height, the depth of my voice, the symmetry of my face, the color of my skin, my genetic potential for muscle developement, etc.
Part is also upbringing: if I've lived my whole life in a family where everyone is obese, I would find a lot harder to shape my body thinner, and it will probably take years to accomplish. So even if some things are mutable, they could change in a timeframe so long that for dating it's normally useless.
Part of what you can change, also, is stacked against fat/ugly men and women: a fit men will probably be good enough with almost any dress, while a fat/short guy will have to make a very careful selection of dresses, limited also by the available budget.
And I suspect that for women it's even worse, at least psychologically.
So no, as someone who has not won the genetic/upbringing lottery in almost any sense, I would revise the percentage of what you can consciously and significantly improve in your looks at 15%.
those who passed it about 30% had acceptable looks
This is a very promising percentage. Did you selected them before meeting them in person, say asking for a photo, or you met them and judged after?
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