The average person does not make meaningful interest or investment income, its not practical to on individual small salaries.

In this case the citizens are forced to save, but the interest they're given is less than what they would have earned by saving the same amount on their own.

Also, the average person in the United States does have meaningful investments toward retirement age.

This assumes citizens actually putp a lions share of their money into more risky investmemt vehicles. For reference, this may not be the case with a large swathes of our older population. Bank rates, t bills and bonds here are generally lower than cpf. If you are a high income earner the contribution is capped and combined with low taxes this is not a bad thing.

What's your source on the yield delta? In fact if you bought regular Singapore government t bills you will actually get a lower rate than the CPF rate. And neither do banks and saving plans give higher rates.