What was the benefit of the French Revolution when, at the end, the poor class of the third estate and women were disappointed, as the promise of equality was not fulfilled?

The ultimate failure of the French Revolution lies in the fact that it never truly lived up to its original promise. In sweeping away a decaying political system, the revolution was supposed to usher in a period of liberty, equality, and fraternity. Yet in due course, such high-sounding principles were never consistently applied to all French people, especially not to women and the poorer classes. Right from the start, women were systematically excluded from participating in national political life. The old prejudice remained that women were physically and emotionally incapable of active involvement in civil society.
The problem here was that the values on which the French Revolution were based were purely formal; they had little in the way of substance. Liberty, equality, and fraternity are so abstract that they can be interpreted in many different, and mutually exclusive, ways. For instance, radical Jacobins such as Robespierre held that liberty was entirely consistent with the use of the guillotine to execute opponents of the regime. The Jacobins also showed how elastic the concept of liberty was by outlawing attempts by workingmen to form what we would now call labor unions.
It's often forgotten that the leading revolutionaries tended to be drawn from the ranks of the middle classes rather than the working poor. As such, the general rights they so proudly proclaimed were often interpreted narrowly to bolster their own class interests. Nevertheless, one could argue that the French Revolution was a success in that it replaced a failing system and at least established promising foundations for a fairer, more equitable society. What it lacked, however, was the political will necessary to put those foundations on a firmer, more substantive footing.