Here is another prediction: the volume of that bet would be nowhere near where it needs to be to make the bet interesting.

Disagree? Create the bet yourself and prove me wrong.

If most people prefer pyproject.toml over requirements.txt, even if it does not support everything you need, isn’t it more likely that you will have to change workflow rather than python remaining stuck with requirement.txt?

I was asking why you need to have a centralized pyproject.toml file, which is apparently why you need constraint files? Most people don’t have this workflow, so are not even aware of constraint files, much less see them as a must-have.

Why do you need to have a centralized pyproject.toml?

My only use case so far has been fixing broken builds when a package has build-)ldependencies that don’t actually work (e.g. a dependency of a dependency breaks stuff). Not super common, but it happens.

But pyproject.toml supports neither locking nor constraints.

Constraints are useful for restricting build dependencies of your dependencies, especially if they follow PEP-518.