This reminds me of Blink Shell, an iOS "shell" that primarily features ssh and mosh. It also implements a bunch of shell commands (a selection of coreutils and netutils), running natively, but with a shim for `system()'. The idea is that you get a shell environment with the same tools (or almost the same tools) as you would on a traditional *nix system.
I think it's a much more practical approach, especially given that Apple seems to be okay with it on their App Store. However, it does leave some things to be desired that'd be totally catered to by the iSH approach, assuming it develops into something much more complete (I tried the TestFlight and while a basic environment was present a lot of things that'd make for a useful environment didn't seem to be implemented).
Not GP, but most of the apps I tried to install and execute I got “Bad System Call” notices from (some going so far as to crash init too). I reported one of those apps to the developer and they indicated it’s fixed on master, but I’ve not had a chance to compile yet (and developer said the same about an updated TestFlight build). Vim was one of the few things that worked decently well, but without a Bluetooth keyboard for Esc it was a little painful. I really like this project so I intend to get builds up and going soon and will be filing much more detailed bug reports (and ideally PRs) soon.