The Soviets, Maoists and Nazis were also secular. I dont think you can objectively say "secularism is objectively better" because it is also responsible for mass violence and persecution.
There's secularism of the American tradition (on paper) that means 'freedom of religion', then there's secularism of the French tradition which is more 'suppression of religion'. That's what they did following the French Revolution, they went on a Reign of Terror and actively killed Catholic clergy and invented their own religion and calendar, which eventually fell away and Napoleon came to power.
The French Revolution was a giant failure; not only did they they replace one Absolute monarchy with another Absolute monarchy, but after Napoleon's house fell they literally brought back the the old monarchy to replace it. The French Revolution is what gave birth to the Fascist and Communist lines of thought. Communism itself being named after the Paris Commune, and Fascism being born out of the right-wing current of Syndicalism.
Secularism, Communism, Socialism, Democracy, Liberalism are all buzzwords with no clear meaning or consistency.
The only thing I respect is Republicanism, specifically Constitutional Republicanism, because it has some clear meaning behind it. And as long as that Constitution is well-thought out and applicable, you can function properly and relatively-fairly whether that's the U.S. or Iran.
The reason why Europe isn't a complete warzone or shithole like its been for most of history is not because they're "liberal democracies" like people keep parroting but because they have a constitution that allows and restricts certain freedoms. Otherwise democracy only leads to one of two things demagoguery** or gynocracy. Still, there are holes in the Western system, which is why its running towards gynocracy and the air of domestic demagoguery is also in the air (Frankly, foreign-policy based demagoguery is still in full-swing). I give it about a century before this Democratic delusion collapses. The philosophers of Greek antiquity up until the US founding fathers wrote extensively against the problems of "democracy" or mob rule.
**See several states in post-partition Africa, the Balkans, South Asia and Myanmar. Democracy only enabled ethnic tribalism and demagoguery.
