Yeah, I went with bare pip for a loooong time before using pip-tools. I like it because it automates a few of the annoying things about dealing with dependencies, but ultimately it's still just the regular old requirements.txt workflow.

It also supports pyproject.toml, so as that gains adoption pip-tools will slot nicely into that workflow, too, I think.

Definitely nothing wrong with just managing things yourself if that's working for you!