I think you are overestimating the actual influence of the Académie then, because it has little. The new words they propose are seldom adopted, and are eventual

I think you are overestimating the actual influence of the Académie then, because it has little. The new words they propose are seldom adopted, and are eventually dropped as they only formalize actual usage. They're not creating a parallel language. The education system is also governed by a different language institution. And just like Spanish, French is governed by different entities in different countries. The French and Québec councils are the most influent ones - and France French and Québec French are also the most divergent versions. The French language is only "powerfully centralized" within each French-speaking country. And even then, only among a few countries. I would say it is actually less centralized than the German language, which has a single institution that oversees orthography in ALL the German-speaking world. The French language has nothing like that.