What? Many companies have tried this. But it has always failed, because even if in theory it sounds like a great idea, in practice it’s a poor experience. In those use cases, you have a much better device for what you’re trying to do — a laptop or desktop.One thing no computer company will never do is create a phone that can be docked to a keyboard and monitor, using the phone screen as the trackpad. Additional power, memory, graphics could be supplied by the dock. Storage could be in the dock or in the cloud.
No one wants to connect a cable, use a wobbling screen as trackpad, have an overheating phone, etc.