Molière is fanfic. Director and co-screenwriter Laurent Tirard, I guess, decided that we didn't know quite enough about the super-famous French playwright, even though we basically know his entire life story because he was famous and rich people liked him. Seriously, he performed his plays in an old-timey room at the pre-listening tour Louvre. I am not even kidding about that, he was a popular guy! So we know a lot about him because he was constantly surrounded by rich people and rich people, as we know, write Wikipedia.
Regardless, Laurent Tirard has decided that Wikipedia is not enough and basically Tartuffe — Molière's professional turning point between straight up farce and comedy with teeth — couldn't have been written unless Molière himself went through a farcical situation of his own. One so madcap and crazy that he couldn't help but poach it for his very own, very successful career. The better to help your literary audience laugh in well-educated recognition, naturally.
So: Molière is thrown in debtor's prison (true). Molière is bailed out by a weasley, wealthy merchant who likes to (a) ignore his wife (b) ignore his daughters (c) suck up to a local nobleman, who is a dick and (d) moon over a rich girl named Célimène who has a salon and who paces back and forth, flicking her fan around like she's gonna kill you with that if her wit doesn’t get you first. Oh: (false). Molière is tasked with coaching the merchant, a gentleman named Jourdain, in performing a play that Jourdain has written for Céli. Also Molière has to pose as a priest for some reason, and later he gets with Mme. Jourdain, who just happens to be a total wellspring of wisdom when it comes to making honest artistic choices.
Behind every great writer is a dead woman who likes to encourage said writer to be true to himself. True story. Amidst all the fanficcy faux-farce (Molière gets chased by a dog! Molière jumps through an open window! Molière, ah, dresses...up...as a priest!) there is plenty of time for Mme. Jourdain to buck epochs of cultural scholarship and make the wholly shocking claim that comedy can make people think about truths. For some reason Molière is sooooo not into that, at least not until 13 years later or something where they basically haven't seen each other for a decade and she's dying and he vists her on her deathbed and she's like "make me laugh" and so he does a running backflip against the wall. Oh, I wish. No, actually he writes Tartuffe and is suddenly completely okay with a little drôlerie. That's French for patronizing your audience, I think.
Making a comedy about a comedic writer in which said writer does not believe in comedy is a confounding set of choices, and we'll all be damned if even the cast knows what's going on. Their choices are half ham, half cheese, and the only real truth generated by the whole honky tonk monkeyshine is that Molière deserves better. You can say things with comedy, you can say all sorts of earth-jiggering things, but maybe first before you try that, you go and you figure out if you have something to say at all.