The have succumbed to an indoctrination technique called "coercive persuasion".
Look it up.
Covid "lockdowns" played no small role.
Isolation is one of the basic requirements for success.
"The term is most appropriately used in reference to a program of political or religious indoctrination or ideological remolding. The techniques of brainwashing typically involve isolation from former associates and sources of information; an exacting regimen requiring absolute obedience and humility; strong social pressures and rewards for cooperation; physical and psychological punishments for non-cooperation ranging from social ostracism and criticism, deprivation of food, sleep, and social contacts, to bondage and torture; and continual reinforcement."
Voilà