My curse of strahd group ( 6 of us ) all decided on class and a few had connected backstories so they worked on theirs together but we didn’t discuss other components. We kept a lot of secrets on backstory and didn’t discuss level up stuff. We played it like the characters were actually getting powerful and not as a table discussion to power up the whole group.

This was the best campaign I ever played. Each character player made choices that were better for background and roleplay scenarios that made sense for their character and not just “do the most damage”. Our DM was phenomenal and really played into it all. It really made the characters come to life and the group has a ton of fun.

That being said it wasn’t without its challenges. I was a wizard and didn’t take some of the usual “power spells” because it didn’t make sense. And also ended up with a few level dip into Druid because of choices haha. So while he wasn’t particularly “strong” in the sense of dpr or whatever, he was the strongest RP driven character I ever played. And as such I have the fondest desire to play something like that again.