For offline software I wouldn’t consider it a problem, but for something that connects to the internet I would want it to have the latest versions of its dependencies.
It looks like the dev has been updating their funding details recently, hopefully they have an update planned.
https://github.com/TachibanaGeneralLaboratories/download-navi/commits/master/
I this is the most effective search I could find:
https://www.google.com/search?q=“Mozilla’s+Firefox+Send”
Not great for a product that is not Mozilla’s Firefox Send!