You postulate this as if this is the biggest blocker for business in this country?
But why do you think this is a problem?
Every country in the world has customs, most are significantly more onerous that SA (especially EU and to some extent the US also)
And what import restrictions do you mean, because I literally buy stuff daily from other places in the world.
I have deliveries near daily from overseas, I order from Amazon.com, AliExpress, eBay, Digikey, RS, Mouser, etc. constantly.
Some courier, some post office.
To date, not a single thing has ever been denied or restricted by SA customs.
I've even had wrong assessments by customs and sent it back and STILL got the parcel with significantly reduced customs.
SA customs doesn't care unless it is on a restricted list, like firearms, nuclear materials, animals, plants, etc. (thing you can probably buy with a permit anyway).
They just want their cut, that is all they are about.
European customs are now clamping down on small shipments. Small items via post office get through but couriers seem to be hitting everyone for even small amounts. Governments around the world are scraping the barrel. It's the same as digital purchases, most now process South African VAT or whatever VAT as per the country you're in.
SA actually has heavy restrictions. For example import max 3 shipments per year without registering. And you need permits for things such as second hand goods, although customs never checked.