I think collaborating with .py files is easier over git.
I could not find a way how to check-in .ipynb file and let reviewer review code only, and ignore the metadata part
if jupytext will allow me to work in jupyter, check in file to git and create MR and let other people easily see, review and comment my code that would be great
I'm not sure why you think it's viable to collaborate with others who don't use jupyter? I mean on any software project, if we don't agree how to compile or run a project, then we usually can't collaborate IMO. Changes become nonsensical (breaking the one or other mode that is not tested by the author of the change.)