Is feudalism suitable to run in modern society? Why?

Not really.

Feudalism rests on personal relationships of allegiance and protection, and on highly balkanized authority, each local ruler being essentially a miniature king within his lands, beside the dues and services owed to his suzerain.

Modern society, on the other hand, is highly impersonal and globalized, just the reverse. Local powers forfeit or delegate a lot of their supposed powers to a higher power echelon, and lose any sense of sovereignty.

Davion has an interesting if metaphorical answer.

Actually, feudalism DOES exist today in many failed or failing states, especially in subSaharan Africa and central Asia. However, instead of calling them feudal lords, we today call them war lords (in Latin America, we call them drug lords).

As the central authority is unable to maintain order or provide a stable lifestyle for the people, the people must in turn throw in their lots with the strongest thug or criminal in the area in order to achieve some sort of stable life for themselves and their families. This often means using their land and their labor to produce narcotics for export to the USA and Europe or it means turning their relatives over for the trade in persons as sex workers (again, for export to the 'civilized' world).

Feudalism as it was in the Middle Ages would not work. After living the way they have been, people would not allowe Feudalism. It didn't really work in the Middle Ages either. Evidence of that is the peasant's revolts. People are too well educated now to let feudalism happen.

Some countries still have feudalism, but they are not as technologically advanced as many societies (like the US or Europe, Japan....).

Although, I agree with that other guy. There are many semi-feudal aspects of our society.

The U.S. government runs capitalism like feudalism. We all pay our taxes and the military protects us from outsiders and ourselves. Is it exactly like a feudal system? No, but it mirrors it. You can say it's run right now in most democratic nations.