The OP posed the question about the French being held in disregard, but my impression, admittedly not rigorously derived, is that the defense is enjoying a bit of a revival nowadays. Rather than being just an occasional surprise reserved for blitz or rapid, it seems to be played at least a bit by some top GMs in classical events such as Norway Chess (Erigaisi's games vs Wei Yi and Caruana) and the Sinquefeld Cup (three games by Aronian). MartinC has already mentioned Ding Liren's use of the French in his two World Championship matches. Matthias Blübaumn, who has qualified for the Candidates, includes the French in his Black repertoire.
As MartinC noted in Reply #1, engines have actually rehabilitated numerous opening lines, including some in the French that were formerly thought to be refuted or unplayable, such as the Armenian Variation (...Ba5 in the Winawer) mentioned by the OP. The old approach of responding to Qg4 with play analogous to the Winawer Poison Pawn remains under a cloud. However, as MartinC and I discussed in another thread:
https://www.chesspub.com/cgi-bin/chess/YaBB.pl?num=1380429314/26 Dreev and Basso's Modern Chess database presents an engine-derived idea of guarding the g7-pawn with ...Kf8, which has proven to be viable, even if the engine's preferred follow-up of ...f6, striking White's center (while also opening up the black king!) seems suicidal. Apparently the concrete lines work out OK for Black, but as noted by posters on that thread, the play isn't especially human-like.
As MartinC and FreeRepublic have indicated in their replies, Stockfish hasn't "killed" the French. In working with this engine in analyzing various French positions, I get the impression that it puts a high value on White's space advantage. It's common to see Stockfish evaluate a position as solidly ⩲, while Leela will consider it equal or close to equal. Leela could be viewed as upholding its evaluation in a game against Stockfish from an engine competition that John Watson analyzes in his February 2025 French Update on ChessPublishing. Although Stockfish must have loved the space advantage conferred by White's massive pawn center in the 5.f4 variation of the 3...Nf6 French Tarrasch, Leela, playing Black, "held nicely" in Watson's words, despite being under some pressure. Watson also made a suggestion for Black in this game, and when I investigated it further, I encountered the phenomenon described by FreeRepublic in Reply #2: playing Stockfish's top move for both sides resulted in the ⩲ evaluation eventually dwindling to near equality.
One thought nags at me: I recall Matthew Sadler writing somewhere that Stockfish's favoritism toward space isn't merely a stylistic preference. Space is a real advantage, just like, e.g., the bishop pair. While this seems like a reversion to Tarrasch's 19th century doctrine, obviously a serious lack of space can be quite deleterious. Perhaps it's simply a matter of degree: whether or not the cramped side has sufficient room to maneuver effectively enough to generate counterplay and freeing pawn breaks.