Very interesting question ... Thank you very much, dear friend, for proposing to discuss this. I myself have been thinking about this a lot lately ...
All that I will say below is, rather, a "game of reason" or "gymnastics for the mind", rather than a political program. Of course, it is very difficult to talk about feudalism after the Great French Revolution, since this question is directly related to the question of universal suffrage. This issue is also connected with the global economic globalization, the worldwide division of labor and the strengthening of the role of state structures in the life of society.
Strange as it may sound, a return to feudalism is possible after overcoming these conditions. And, strangely enough, but the way for this is prepared by some leftists - anarchists, green and so on. In the modern world there is a deaf discontent with the omnipotence of the state bureaucracy, there is a tendency to release from the guardianship of the state. Also, some social groups have a desire to isolate themselves from the modern state, to organize the life of a small community that will live according to the laws of direct "grassroots" democracy. If such a movement is of a mass character, then modern states will gradually die out (Karl Marx seems to have written about this), and the emergence of self-governing communities sooner or later, but will lead to the division of labor, the formation of a new aristocracy and the revival of feudalism. I think so. But it will be a new feudalism, a new aristocracy, and new kings. And it will not happen very soon.
Personally, I really like feudalism. This is a very honest system in which everyone does his job: a simple people creates products and pays direct taxes to the seigneur; The senor defends his vassals, carries out a fair trial and takes care of maintaining order. Under feudalism, the rural community has a direct "grassroots" democracy and settles the issues of daily life itself, and the seigneur delegates the resolution of issues of a larger scale that the community can not solve. With such a system, not only the state bureaucracy ("state idlers") dies out, but universal suffrage-the basis of the republican system-becomes unnecessary. There is a decentralization of power, city dwellers live according to the city charter, which is given to them by the King or the Emperor. So lived the Holy Roman Empire, and to this system society will ever return.