If the world were to become without religion (the kind which claims someone and/or someone supernatural exists), without it being caused by coercion, and as long there were effective checks and balances preventing the existence of totalitarian states/governments, then the world would be a better place. Today some oppressive highly controlling secular ideologies exist which are like religions and which some call secular religions. One is communism, at least in the form practiced in North Korea, in the form that existed in the former U.S.S.R., and perhaps in the form which exists in the People's Republic of China (excluding Taiwan). Those kinds of secular 'religions' would also need to cease to exist if the world were to become entirely without religion and become a better place as a result.
But there are other ideologies (and/or philosophies or worldviews) which are sometimes called religions which are not dangerous and not controlling, which provide a net benefit to human society. One of those is Secular Humanism, which is now a days sometimes simply called Humanism. But I think even Humanism may have some flaws (at least, some of its ideas are too liberally permissive for me [and some of its ideas in my mind show a lack of appreciation for certain living entities, such as human embryos and livestock, for me for me to feel fully comfortable with Humanism]). [There are however some who call themselves Humanists (or who at least identify with much of the ideas of Humanism) who are pro-life and who are for animal rights; see https://www.prolifehumanists.org/ and https://thehumanist.com/commentary/should-humanism-extend-to-animal-rights/ .]
I think it would be beneficial if institutions continued to exist which teach and promote morals and ethics, provided they don't teach supernaturalism, and provided they encourage critical thinking instead of blindly accepting dogmas. Such institutions could provide parents with information to assist in raising their children to be good, moral, ethical, and sensible people. Such institutions could also help prevent the rising into existence of evil totalitarian governments. Such institutions could also resist current evil totalitarian governments.