> they had to buy the local supermarkets in the first place

When foreign owners extract profits to recover their investment or pay whomever, wealth is in fact leaving the country - because they still own the capital (stores) yet get money back.

It's not clear cut based on this. They could have invested beyond price, brought knowledge, improved efficiency ... It's also possible they are in effect extracting wealth colonialist style, which is something to beware of - at scale it can have severe consequences for local economies.