I've gone from Sunday attending to more lax and agnostic. Does that count? If so, is because of how inconsistent the actual practical actions of churches I've been to. Started protestant, but enough were hypocrites (remind me of the pharisees) so I stopped going. Became catholic and loved it, but the way the church has continually terribly handled the sex abuse pedo cases has disgusted me. Priests should be held to a higher standard, not lower.
Additionally, I don't wanna be associated with the people who are Christian on TV. All the right wing Republicans in the US govt are terrible people. Whatever they say they are, I don't wanna be a part of that. It's hard to reconcile "love your neighbor" and then legislate their live away or give crazy people unfettered access to guns.
On a more practical level, I like a lot of the charity work and compassion taught by Jesus. I'm OK with the spiritual aspects. I cannot get behind the church's message (mostly protestant) about personal relationship with God. If God intervenes, then that means it's his responsibility when he doesn't intervene and a lot of terrible things are his fault. If he doesn't intervene, then a lot of what the church says is wrong. It doesn't add up.
Your response caught my attention because I had a similar path, though only in Catholic Church, practicing religion in my 20’s, but moving away after mid 30’s.
At a practical level Jesus was right, showing compassion, living modestly…. but the interpretations of the churches - not only catholic - all the pomp and circumstance around mass, preaching, shrouding secrecy, asking the poor for money, etc. made me question churches in general.
After studying some philosophy, and learning meditation practices, I believe churches play an important role in society, including that prayer enables the masses to experience meditative states that have important health benefits. Religious teachings give something in which people can believe in, instead of facing uncertainties of life alone.
Also in many cases throughout history, churches anchored small communities together.
I believe people should experience church to decide on their own, but not being guilted to staying. Each person should be able to discern, choose their path, but there are always the crazy ones out there guilting and trying to impose their beliefs on to others. That is not right.
One big problem with your last paragraph: Baptism and many other rite to join religions happen at a very young age. These children know no world without the belief almost everyone around them practices. It's getting their norm how live is. Leaving gets hard, it means leaving your life behind.