If it was really "just an exit", people wouldn't buy the IPO and it would flop
Of course people believe there is room for more growth, that's why they are buying it
Even in this thread you can see people (not me) arguing that the IPO is too cheap and it's easily worth 3 trillion $ like numbers mean nothing
Sometimes, there is no logic behind what people do, ultimately hoping to strike gold once while wasting money otherwise.