> If you go to the Flanders region people will certainly tell you they speak Flemish.
And they would be right. They do indeed speak the Flemish dialect.
> That's an opinion, not a fact, and one that depends on who you ask and where
I don't see how it is "an opinion" if Flemish literally adheres to "Standaardnederlands" (https://nl.wikipedia.org/wiki/Standaardnederlands). Your analogy to German doesn't make any sense here. The Dutch language doesn't adhere to some "Germanic" standard language or anything, and barely has any grammar rules in common with German (even though the languages are very similar).
And they would be right. They do indeed speak the Flemish dialect.
> That's an opinion, not a fact, and one that depends on who you ask and where
I don't see how it is "an opinion" if Flemish literally adheres to "Standaardnederlands" (https://nl.wikipedia.org/wiki/Standaardnederlands). Your analogy to German doesn't make any sense here. The Dutch language doesn't adhere to some "Germanic" standard language or anything, and barely has any grammar rules in common with German (even though the languages are very similar).