You can do a lot of the things you want, just not necessarily in an ergonomic way. I think eventually it will be a decent platform for the kind of user who writes excel macros and basic automation scripts, but not for actual programming unless they make radical changes to what's allowed in the app store.

iSH gives you an Alpine linux environment, running in x86 usermode emulation. It's still only a beta though, I have no idea if it would even be allowed on the app store.

Pythonista gives you a python environment, it's good for automation type things. You can do stuff like run an HTTP server locally and access it from the browser.

Inspect is a neat web browser with some basic dev tools.

Scriptable is a bit like Workflow/Shortcuts, but in Javascript.