If there were no women, there would be no society. (Also if there were no men.) Therefore sex (analytically distinguishable from gender) is one of the indispensable fundamentals of society.
If there were no workers, there would be no society. If there were no capitalists, society would still exist (and in many historical instances has existed). Therefore workers are an analytical category as fundamental as males/females. (Workers in the analytical sense include both manual and nonmanual workers.)
If there were no homosexuals, society would still exist. Sexual preference is not a fundamental category, but a development of luxury, superstructures, whatever you want to call it. Historically, it is a late-expanding movement.
If there were no white people, society would still exist. If there were no black people, society would still exist. The same is true for any racial or ethnic groups. Therefore race/ethnicity is a derivative category, not fundamental.
We could fiddle with thought experiments of technological utopias in which males were replaced by biological engineering; and also in which females were replaced. But there can be no technological utopia without workers to set it up. Therefore labor is the most fundamental of all social categories.
Until an all-robot society disposed of human labor?
