My point has not been to dissuade you from what you prefer to use, merely to highlight the alternatives. And with how you're describing Termux it sounds like it doesn't need a package manager (app store), anything more advanced to describe files than ascii/binary pipes (share sheets), doesn't need to natively interact with the cloud (fopen vs Files app APIs), definitely doesn't need a GUI outside of ascii art or whatever random xwindowing GUI is supported...
I will say there's innovation in a platform that's completely untethered and allows processes to run as root. Jailbreaking on iOS early on provided much innovation. Similarly diverse hardware gives you lots of options too.
But let me know how other apps -- native Android ones -- interact with that app. Can Google interact with it? See, that's the difference an OS standard makes. The app you're describing, Termux, builds on top of existing Linux standards, including GNU utilities and distributions building and packaging apps. If you jailbreak on iOS, you can install deb packages too. It's not like the kernel doesn't support these features. All we need, obviously, is a virtual machine or emulator powerful enough, and you've got your Termux on iOS.
I'm absolutely not arguing against it, I'm just saying, "it's an app!" And the platform features on iOS are more widely distributed, adopted and often more innovative, than the equivalent on Android, and that's where the power comes from. Sure, one app, like iSH or Termux, will give you superpowers, and rooting or jailbreaking can give you even more control over your phone. But if the platform's not innovating, 90-95% of users won't benefit. And if you haven't found advantages to touch screens, cellphone form factors, music subscription services, and other forms of interaction beyond terminal, well ... I'm sorry we haven't made much progress technologically since Unix time sharing that you find useful...