Possibly, but the benefit of not allowing it to be dynamic (or at least not varying across platforms), is that lockfiles can be generated on one platform and installed on other platforms. This is the not-technically-correct-but-very-practical simplifying assumption that poetry presently makes with its lockfile.
This addresses the universal pain felt around the world by engineers using windows or macos and having to commit lockfiles that run on linux CI or linux production servers. And here is where I expect folks to start yelling “docker, docker” at me. We don’t all want to (or need to) use docker for something like this.