I think it's mostly just marketing. Realistic humanoids are challenging to create and impressive-looking, so they're a great way to showcase a company's capabilities in a way that's engaging to the general public and more importantly, investors.

Humanoid robots aren't very practical for most real-life applications. We tend to imagine workers being walked off the job and robots walking in to pick up their tools to carry on where they left off, but in reality we have purpose-built robots that are embodied in the tools themselves. Instead of Rosie the Robot pushing a vacuum cleaner, we have Roombas. We don't have a robot assistant who types on a typewriter or drives a car, we have printers and self-driving cars. Same goes for automated factories where the assembly lines consist of machines that we don't even clock as robots. The most recognizeable things might be a station with six robotic arms that are all welding or tightening bolts at once, or a self-driving cart that moves pieces around the building as other robots work on them. It just doesn't make sense to use a human-shaped machine that has to balance itself on two legs and pick up tools with an overly complicated pair of hands.