As the authors said - no more virtual envs.
A basic example of something that would break if the environment is not activated is binaries, like mypy.
You have a script that calls "mypy"? Gotta be in the virtual environment to invoke it, otherwise the executable might not be found, or worse, it might run another executable.
One of the thing that the virtual environment does is modify the PATH to lookup executables from the virtual environment first.
This is to ensure that when a script calls binaries like mypy/python, it's going to find the same binary from the environment it's currently running in.
Typically if the environment is not activated, python is going to lookup to /usr/bin/python and might be something else.
This is most noticeable when there are different versions of python on the systems and when having scripts that invoke themselves.
I really like writing one-off or sporadically used commandline tools. Loading a virtualenv or navigating to a directory before executing kind of sucks. Generally, I install into my homedir. I haven't read through or tried this out, but it seems like it might better address this use case.
You're right, this seems to be very similar. To me, it looks like it removes one abstraction layer of pushing-popping the environment.
Another issue with wrappers is how quickly it executes. It's not a big deal for most executions, but for --help or building up a command pipeline it's really annoying to wait a second or two on each execution. That slow startup time also shows up when you start integrating it into automated processes.