My child moved to front facing at around 2 or maybe 2.5 at the oldest (had to go back and lock at old pictures to confirm, she’s 12 now). Parents who obsess over things like keeping their kid rear facing until 5 or in a booster seat until 12 are just neurotic, IMHO. They’re probably the same ones who won’t let them ride their bikes around the neighborhood unsupervised or walk/ride the bus to or from school.
Ehhhhh, what's your problem with booster seats? Those are just to get the shoulders into the design zone as needed for the typical 3-point seat belt.
It's based on size (shoulder height measured in sitting position) not age.
I think some 5-point seat belts allow a much wider design zone so won't need boosters by the time the children outgrow the front-facing bucket seat.
My wife's argument to keep them rear-facing as long as possible is that it's closer to laying down and it helps them sleep.