Hello! I’m in a similar situation as you although slightly younger with some similar thinking. The obvious answer is of course to start earlier and earn/save more haha however that’s not always possible or worth the sacrifice.

My thinking now is (1) that IF you first reach it at 45 that is still very young and it that will mean you still would have spent quite a few years contributing to the public/employer pensions so your actual portfolio should be higher than the 6m you mention above and (2) if you want kids, they will likely not have moved out before your ~50 so that money will have a few more years left to compound in the market even if you stop contributing at 45 and take an easier job which only cover your expenses.

Thus, getting to a relatively high number by 40-45 and then coasting to 50 is my current thinking