Pipenv only targets applications; Poetry targets both applications and libraries. Pipenv has quite some drama behind it that I do not want to get into; in contrast, Poetry's development has been quite professional. Pipenv enjoys better tool support, e.g. it is recognized and supported by VS Code; but Poetry does not have the same level of support.
The drama was surrounding false advertising so to speak. Pipenv promised a lot but did not quite deliver, much like the earlier days of MongoDB. But more importantly, it pretended or at least heavily implied it was an official PSF-affiliated project, when it was not. How that claim was substantiated was also subject to drama.
It also had no releases for over a year, even though the master branch was getting frequent updates and the performance of the last release was atrocious (and I'm not sure if it has improved much).
From memory, there was a whole thing where pipenv, created by Kenneth Reitz of requests fame, was misaccurately portrayed as the official successor to pip when that wasn't true
I just moved a project from pipenv to poetry at work. My biggest issue with pipenv is that you can't selectively upgrade dependencies. Trying to `pipenv update xyz` basically blows away your lockfile and updates everything. There's a command line flag to be more selective but it doesn't work. I found an open GitHub issue about it that's years old.
Poetry by contrast works pretty much like any modern dependency system you'd be familiar with from another language like cargo, npm, or hex.
