I share your second guessing about religion and have wondered if losing it will simply lead to it being reinvented. However I am not sure cancel culture activists are looking to win anyone over. It’s more that they want to use fear and consequence to deter and suppress others, in particular to keep them from expressing ideas that oppose their own ideology. The idea is to let the opposing side starve itself out while only your ideas dominate and propagandize the next generation of minds. It’s the same tactic advocated by authoritarians of all political persuasions.