What are you basing that on? It had a release in 2022 and last commit is 7 months old. It probably hasn't needed any new features in a while. I'm not sure how often it would need security updates.
Ah, I see now there's a note in the README[0]. It sounds more like it's in maintenance mode / understaffed than completely abandoned, but I suppose it's worth being aware of. sshfs has been a killer feature for me on my machines for years for things like playing back stuff from my media library in mpv while it's stored on another machine. I found it to be easier to use and less glitchy than NFS. So I will likely continue to use it.
I am curious how much stuff sshfs itself does and how much is just handled by ssh or fuse on your system. (am not a programmer, unfortunately, before someone says to read the code)
People also have different ideas of what "unmaintained" means. The earlier poster was likely highlighting the common misconception that software must be constantly changed in order to be considered maintained.
Personally, if something is called secure shell and it's not secure, then it's broken. Maybe I'm weird.
The definition of maintained in indeed subjective, so I don't think it can even be called a misconception. People just disagree on what it means, but there can't be a single right or wrong answer.
Some people prefer secure software to be regularly updated and audited and won't trust other programs. I think it's a perfectly reasonable position, but I also know not everyone will think the same way.