I think it comes down to two main reasons:
1) Insane levels of regulation and bureaucracy, with a sprinkle of corruption.
2) A banking system that seems diversified and modern on the surface, but is actually an oligopoly and extremely behind technologically.
That being said, I think there is a lot of talent in the country. Also, at least among the younger generation, there has been a shift towards learning English (instead of French) to better work with the US market.
Side note: I’ve always wanted to work on a fintech startup for the Tunisian market to help with point (2) above, but as soon as I think about dealing with the banking system and government regulations, I reconsider.. One interesting player in this space is Flouci.