Since 2021, newer sets have been favouring Climax combos for midgame and endgame. As such, you can make an educated guess on what your opponent's deck will have by looking at his Waiting Room in the mulligan, especially if he ditches a climax during that phase.
Well, just as it is written above, the cardfight vanguard game is one of the best. Yes it didn't start well but after it came in tcg things are steadily changing. Yugioh was the boss as always( still has the Guinness record. But think of this: with the newest formats always depending on 2 maybe 3 decks that will be banned in one or two lists, all decks made a form of income and so on, the game has lost its value. Players out there search for something fun easy, with no rules (chains, priorities, sp summon chainability etc) cheap( most vanguard cards are cheap with the most expensive being at 30 $), and also new, fresh you could say. All that is the summary of vanguard. The rules are easy, the game is fun, the whole thing has some rules taken from yugioh, others from magic others from many games, but it only took the best aspects of those games leaving out all the imperfections.