>>50067621>btw Spanish and French also have dialectsThe situation is different.
The French government managed to practically kill all native languages besides French; they've been doing this since Napoleon, but the XIX century was specially bad at that.
Spain did attempt something similar with Francisco Franco; however, as early as the Reconquista, local languages have been declining. Catalan is rather the exception, being alive and kicking; Basque and Galician are somewhat OK, but Mozarabic is dead, Aranese is locked practically in a city, Leonese is moribund and fragmented and Aragonese, well... lots of those were parts of a continuum that doesn't exist anymore, so the whole thing is "tidier".
On the other hand, the German unification was far later; Standarddeutsch imposed itself far less than castellano or français. You have a whole messy continuum of dialects with no definite "borders" not existent in the other two.
