Great ! With help from the Community, I can answer my own question. Maybe someone can benefit from it too. The main point I overlooked, as pointed out in the comments by several users, was that French is growing as a second language in Africa for different reasons than English is worldwide.
French is used as a lingua franca in several multilingual African countries where no native language is currently doing the same. So it’s more practical to continue using French. Also, favouring a local language could be seen as a threat by speakers of the other native languages. The Ivory Coast, Gabon, the Congo, and the Democratic Republic of Congo (among others) are countries where French is used for the above mentioned reason.
English (Nigeria, Ghana, South Africa, etc.), Portuguese (Angola, Mozambique) and Swahili (Kenya, Tanzania) are also used in other African countries for similar purposes.
Speaking of which, that’s also the main reason why English has remained a dominant language in India in opposition to Hindi. The southern non-Hindi states opposed the promotion of Hindi, seeing it as a threat, and so English is still used more than seven decades after independence.
Globally, English is used as a second language because of the huge economical and educational benefits it provides. Of course, it also serves as a lingua franca around the world.
Now, it’s definitely possible that some French-speaking African countries could switch to English sooner or later, especially in countries where another language already fulfils the role of a lingua franca.
For instance, in Algeria and Tunisia, where Arabic already serves as a lingua franca, discussions about a possible transition to English are already under way. In Senegal, French is gradually being replaced by Wolof. In Morocco and Madagascar, English is becoming more popular among younger people than French.
In Vietnam and Cambodia, French has been in decline for decades. The main reason is again because another language (Vietnamese, Khmer) is used as a lingua franca for the whole country. In Laos, a decline has also been observed, but French is surprisingly still present to some degree up to the present time.
After heavily browsing the web, one of the main reason that comes out about why the transition hasn’t already occurred is the huge cost associated with it. Training of new teachers in schools , new textbooks, replacing administrative paperwork, etc. So it’s just too costly to do it currently for most countries.
Another reason is that France would vehemently oppose any transition to English. That can be seen in Rwanda where there’s a controversy about why the French government supported the pro-Hutu faction in Rwanda in the 1990s even during the genocide. As can be read in the link, the French government feared the pro-Tutsis rebels, trained in English-speaking Uganda, would change the official language from French to English, which they actually did.
Also, the local elite is used to speak French in those countries, often having done their education in France. Breaking habits is hard (I hope I don’t need to prove that).
The transition (from French to another language, especially English) could occur in some countries where another language already serves as a lingua franca. For now, it hasn’t because:
- the cost to switch is huge
- France would vehemently oppose it
- the local elites are used to French
So yes, French is growing as a second language in Africa, but the growth could be less than currently expected if some countries decide to transition to English, a transition that could definitely be possible in some of the French-speaking African countries.
Thanks for reading !