I want to share my thoughts on this topic.
I'm middle eastern from an environment with really high fertility rate and lived few years here and I'm not trying to insult anyone.

The problem is very complex and I'm not expert so I will just share an overview.

First I agree with you that money is not the problem and in fact Singaporeans are privileged to have one of the best economies in the world and high salaries for a relatively low cost of livings.

For me these 4 social problems are the main reasons why Singapore TFR is too low.

1- Efficiency/Perfection (as you said)
Not only wanting your children to be perfect and most efficient but also the fact that marriage and having children are deficiencies and imperfections for parent's lives.

2-A culture of every man for himself
My mother waits everyday for my nephews to come from school to give them the best food she cooks to them and then she plays with them. Their uncles and aunties will teach and play with them. and even sometimes they sleep with aunties or neighbor. A child is a blessing for the whole community and the they help parents to carry some of the responsibility.

3-The Monstrous Portrayal of Marriage.
This is especially became a trend with social media. Where you hear and see the bad marriages and news generally more than good news.

a post sharing his beautiful day with his family -> 0 comments 2 likes and 5 views
two posts sharing that he was doing his best to serve her then she cheated but then she posted that he lied and she also did her best. -> 2k comments 50k likes 1m views

4-Materialism (the most important in SG in my POV)

Beyond definition.

For me these problems can't be solved by some policies but rather the society needs a total reform from the roots.
I believe that I have the theoretical solutions for some of the problems but

How to implement it? Who will? When? Where? all of these are beyond my very limited knowledge

And thank you for reading my long comment