If I ask you about your favourite Hindi comedies, Dhamaal, Welcome, Golmaal, and Housefull will feature on most of your lists. However, the same can't be said about their sequels.
That's the problem with Hindi production houses. Instead of preserving the writing, characters, and simplicity that made the first film special, they assume the success came from scale. So the sequel gets a bigger budget, more stars, CGI, louder gags, and jokes that try too hard.
Take Dhamaal. It worked because of its simple plot, grounded madness, no romantic angle, no melodrama, no songs interrupting the story, and a cast perfectly in sync with the film's tone.
Most importantly, the comedy came from the characters. Roy, Adi, Manav, and Boman were greedy, foolish, and constantly making bad decisions, yet somehow remained innocent and lovable. You laughed at them, but you also rooted for them. The humor flowed naturally from their personalities and situations, not from punchlines forced into every scene.
Dhamaal's sequels (we already have two, and the fourth one is coming soon) changed that core completely. They kept the brand but lost the soul. Big stars, item songs, glamour, repetition, bad CGI, and bland jokes.
Maybe that's why, nearly two decades later, people still remember and quote scenes from the original, while struggling to recall anything from the sequels.