Key difference: slaves told to get free if possible; wives never told to escape marriage

1 Corinthians 7:21: 'if you can gain your freedom, avail yourself of the opportunity.' Also v.23: 'do not become bondservants of men.' Slavery is presented as an unfortunate situation you should escape if possible. Marriage is never presented this way. Nobody is told 'don't become wives' or 'if you can get out of marriage, try.' These are obviously not based on the same principles.