Outlawing religion wouldn't solve the problem, religion is used as an excuse to further political goals and rally people under ideologies, it's not the cause of it. If there were no religion, they'd just find something else to rally people under be it ethnicity, political ideology or something else.
Erik Prince, founder of Blackrock, just happened to have a sister, Betsy Devos, who may have colluded with him to dismantle the efficacy of public education in an effort to keep a uneducated populace that votes for continued blind military spending, enriching their family beyond their wildest dreams.
And she's still pulling strings, still fucking up America's public education for personal gain.
Yes many countries have tried in the past. Communist countries, USSR and the Khmer Rouge.
If religion disappeared overnight, extremism and violence would still exist. Humans are tribal superstitious people. If mankind has massive physical brawls over sports teams then they’ll find something new to fight over even if it wasn’t religion.