Collectivism has been tried in many forms in human history and always failed.
The most recent examples include the Soviet Union, Cuba, and even Venesula. A recurring trait of a collectivist government is bureaucratic cronyism, for the good of the people of course. A representative republic tends to keep this in check, but rampant democracy coupled with a very good propaganda machine, can sell enough of the public on the collectivist approach.
This then invariably leads to large bloated bureaucracies which tend to support themselves by supporting their friends. We saw this with the Healthcare bill which started to sprout waivers almost immediately, mostly to unions and groups who supported the administration like AARP. We have also seen business deals where it appears that an inordinate number of former Goldman Sachs executiuves seem to have found cushy government jobs. Not bad for a group that had a significant role ion causing the financial meltdown.