Arrived at the airport at 1 am and booked a hotel online. They also provide shuttle service. Is it safe? Will there be bad people posing as bus drivers?

If you book a hotel and the hotel provides a shuttle bus, then the hotel will be directly responsible for you, which will be very safe. No hotel dares to risk its reputation. Moreover, the pick-up card held by the driver who picks you up is also your name and number, which generally needs to be confirmed with you repeatedly when picking you up. I don't know where you're going, at least everyone I've been to with a shuttle bus service is like this.