Pyright is much much better. If you're starting a new project or work with people who understand the value of type hints and want to actually fix them (ha yeah right) it's a no brainer. It's also the default in VSCode which is nice. Oh and they guy that maintains it is a bug fixing machine.
The only reason you should consider MyPy is if you're adding types to a big existing project or you're working with people that don't get it. MyPy has way more "eh whatever" options so it doesn't give you a barrage of errors when you run it for the first time.
But other than that you should use Pyright. No contest.