You can get the answer very easily.
Personally, you contribute 20%. Employer contributes 16%. By right, you should be left with 80% as take-home pay.
Alright, so it's 80% in your bank vs 36% in the CPF account.
Do you twice the amount in cash as compared to CPF?
Alright, I forgot to deduct your monthly expenditure, let's say you spend 50%, so you're left with 40% of the salary that you actually save.
Now, does your bank savings match your CPF? Are you investing better than CPF?