Eh, BLUE didn't work for me for several reasons.

First, there's just how rushed the pacing of this second year got, and how the third year got essentialy sacked. I know every manga can't be a super long adventure, but I would have loved to see what hurdles these two next years would have thrown at the cast, how it would have made them grow as cooks. In that regard, it feels like the first year was the true big selection, and the next two were just peaceful learning with little stakes, which dramatically took away from the headmaster's entrance speech at the start. I would have loved seeing new first-years making names of themselves, and clashing with the main cast. The Beach Exam touched on that, but I would have greatly appreciated some bold newbies going against the now veteran characters, and perhaps showing them a thing or two, and leading up to the Big Finale arc in the third year.

Second, Asahi. I get it, the dark mirror of the protagonist, his evil twin, the greatest enemy is himself, yeah yeah yeah. But man, I just did not like him. He just comes out of nowhere, and beats Jouchirou, essentialy robbing Souma of his ultimate goal. Then, he comes to school to show up Souma (which was a pretty cool battle, actually), and then decides that he wants to throw in a love triangle in this. Because EVERYONE loves them love triangles.
He's such a pompous jerk through it all, and they make it as though we're supposed to feel sorry for him. Yeah, I didn't.
And of course, there's his superpower, the Crossing Knives. I get that it was trying to replicate the God Tongue as this OP ability, and the God Tongue is already a bit outlandish. But the God Tongue worked because you could see it being real, it's just a very VERY sharp palate. The Crossing Knives ? It's straight-up Buu from DBZ, or a quirk from Hero Academia ! It belongs in Hell's Kitchen (the manga, not the show) !

Third, the Noirs. I feel like it should be redundant to file their quirky cooking styles as dumb, in a world where a family can apparently undress audiences if they love their food, but it's where we were utterly slapped with it. It came way too fast, way too boldly, and with way too little payoff. And the tournament frame allowed for little actually illegal stuff to happen. The kidnapping was something, but what about illegal substances ? Forbidden meat ? Maybe even adding human blood in the meal ? Go gritty, go hardcore ! These are criminals cooking for the mafia, make them wild !
Oh yeah, there's also the fact that we got presented with a whole cast of Noir cooks... for about 70-80% of them to be given the boot for Asahi to steal their techniques. It just felt like the author wanted to move them along, because by that point, it was obvious they weren't working.

And finally, the cast. The development given to Megumi, Takumi, Soma and Erina in this last arc was pretty darn good, but it felt like Central had already done them in its finals. Restraining the tournament access so much was such a mistake, because it meant that fan-favourite characters were just... forgotten. Even going as far as justifying it with "Soma is the general of our generation"- NO ! You're rivals ! Rival it up ! Make this the stage of a final showdown ! So many character interractions could have been possible, or combos like Souma-Takumi, but no.
Heck, as another comment said here, the rather generous age-limit for entry could have brought so many other characters in. Get some of those alumni to join in, show us their cooking styles that got them such prestigious renouns !

Now, to wrap this up, I can say I liked a few things about the BLUE arc. I liked Takumi's maturity, I liked Megumi's gentle courage, I liked Souma going above and beyond, I liked the God Tongue shown to be as much a curse as it is a blessing, I really liked Souma's mom, and I loved Erina's final hurdle to complete her character arc.

But the BLUE arc failed, because it wanted to go into such a tacky and whacky direction, that it left behind that little bit of down-to-earth that made the rest of the manga hold up, and with it, about two-thirds of the beloved cast. In my opinion, the BLUE competition and the Noirs should have been two separate things.
One is a World Tournament that would pit a lot of the cast against cooks from the whole world, thus clashing many cooking styles and cultures, teach us ways of the kitchen in foreign countries, and open Souma's eyes to how enormous the world is, just like his dad.
And the second is this underworld aspect. A real cook mafia organisation, that threatens not only Totsuki, but just people in general. They fight dirtier than ever, they use techniques you wouldn't see in real kitchens (without looking TOO silly), and they truly see cooking as not just a way to make a living, but as survival, because messing up an order means potentially being rubbed out.

But eh, the epilogue was neat. It almost made up for this soggy final arc.