At least Progressives will survive without Conservatives, whereas Conservatives will not survive without Progressives.
Progressives know how to join together and pool their efforts so those who do not wish to labor don't have to, businesses exist to please the collective rather than to exploit others for profits, and all necessities of life are provided in unlimited quantities to everyone for free. At the end of the day, everyone joins hands and lives in blissful harmony knowing that they have helped the members of the collective ragardless of individual contributions.
Meanwhile, Conservatives eat each other with competition. Nothing has ever been gained when self interest is the goal.