I understand this is a common suggestion in the developer world, but I think it is self evident that doing so takes a fair bit of time. The parent said they’ll just have to switch, which I expect is much easier than packaging a DE yourself or even sharing responsibility.

Does it? I'd imagine you could collaborate with the Mint developers, most of the hard work in packaging seems to be done there already.

There is specifically a version of Linux Mint Cinnamon which is based on Debian and not Ubuntu

https://www.linuxmint.com/download_lmde.php

Still though, I have to imagine there is a lot of work / knowledge required to maintain Cinnamon on Debian proper.

But we know nothing about the person who said they will switch DE’s. We don’t know if spending time collaborating with Mint developers is a reasonable suggestion for them. I just want folks to realize that while recruitment is important, not every single Linux user should be expected to code for Linux. For example I’m a heavy Linux user but I’ve got my hands full maintaining my own open source robotics projects. I do not have time to take on something like this. I hope we can be understanding when people don’t have time for this kind of thing.