Pylance is Pyright (open source) plus custom Small Language Models and other proprietary sauce. Pylance isn't sabotaging Pyright, because it is built on top of

Pylance is Pyright (open source) plus custom Small Language Models and other proprietary sauce. Pylance isn't sabotaging Pyright, because it is built on top of it. You can find alternative extensions that are "just" Pyright. (They have a fraction of the users because the SLM-based magic of Pylance is a nicer experience if you can "afford" it [based on your principles].) Pyright is maybe sabotaging competitive projects MyPy and Ruff by being "knighted" as a part of Pylance, but that's not generally how open source competition is seen to exist. There also doesn't currently seem to be competition for the proprietary bits of Pylance outside of the LLM space. That's maybe catching up quickly, but Microsoft's more dedicated SLM models might still be leaders in the space, and Microsoft wanting to keep models proprietary while they are competitive shouldn't be a surprise.