I've put all my and my wife's CPF-OA and SA in our condo and unit trusts. If MAS, GIC and Temasek go bust, we'll still have our condo to show for it and funds with unit trusts, not with MAS, GIC or Temasek.
There's only a few dollars left there other than our Medisave Accounts. Medisave is daylight extortion for protection money. It's the same as paying for medical bills before you fall ill.
We don't "contribute" to our CPF since we started our own business some years ago. We hire a few employees and "contribute" to their CPF but I'd frankly admit, we (as all other employers do) use their own money to contribute to their CPF.
For example, I'm actually willing to hire you for $2,000. Taken employer CPF into consideration, I'd offer you about $1,800 basic, from there employee CPF has to be deducted too and your take-home becomes about $1,600. All your CPF are all your own money whether you call it employers' or employees' "contribution."