my take on this whole thing is:

… and there it is! A tool to fix the fallout of the practice of always using venvs and always version pinning.

Nice.

I have no need for this kind of tool, because I don’t have version conflicts. Does this manage my dependencies in other ways?

No idea what .in is.

.txt is split out into .lock and .unlock.

Are they still .txt or is there a new file standard for .lock and .unlock?

pyproject.toml

.toml,

The only thing you have to unlearn is being so timid.

No, that’s… against community rules :) I don’t like the common use of venvs or .toml very much and I don’t like their use by other people and “timid” is also diplomatic. So you’re getting timid, and we get to get along and we can agree to disagree on the use of .venvs and we can wish each other a pleasant day.