Raw coins are still very common in the foreign stuff. I feel like the only real reason to have foreign coins slabbed is to play in the Registry. Take that away, and now I will not be slabbing any more foreign stuff.
Good news is, I don't have to put up with the 3 month wait time anymore.
Like US coins, some world coins are worth grading to authenticate.
The other primary reason would be due to the price difference between raw and graded coins. South Africa coins graded by NGC and PCGS in higher grades (mint state mostly) can sell for large premiums to raw coins.
Most better world coins generally though are not graded (which can easily be verified by checking the pitifully low census pops for most of them) and even of those that are, for the series I collect, are not included in the registry anyway.