Virtual environments are an incomplete solution at best. In particular, they really don't help much with the use case of wanting to install a tool: if you're installing a tool and not just setting up a development environment for working on a specific project with its dependencies, then you probably want to make that tool usable without activating its venv. The virtual environment capabilities shipped with Python itself don't really have any affordances for that.
Virtual environments are an incomplete solution at best. In particular, they really don't help much with the use case of wanting to install a tool: if you're installing a tool and not just setting up a development environment for working on a specific project with its dependencies, then you probably want to make that tool usable without activating its venv. The virtual environment capabilities shipped with Python itself don't really have any affordances for that.