I don't know about C#, it's not an ecosystem I swim in at all, but there are multiple python options (including Pyto, the venerable Pythonista and jupyter notebook hosts like Juno & Carnets). There are js environments like Scriptable and Play.js. And it's not Xcode but Swift Playgrounds offers, of course, swift including swift.ui and the ability to redistribute those projects (with some limitations) including submitting directly to the App Store.
I get it; I use an iPad a lot for a great many things. It's not perfect - I have a long list of things I would like to see addressed. Low effort complaints like "let me know when I can code on it" are just that though; low effort. So those who complain "how to code on it?" or about how it exactly match the workflow they use on a completely different platform etc just sound.... whiney.
Low effort noise when some basic infrastructure could enable so many other workflows. I like my iPad, I use it every day, I hope to use more with less friction soon-ish. Yup, same thing every June.
I mean, on the other hand, there's plenty of other things I could code on. I have a Nintendo Switch with root access, but that doesn't make it an appealing device to write code with. Hell, SSH could run on Apple Watch with a Bluetooth keyboard. Once again though, there's simply no point. You may as well get a laptop, it sounds like you only intend to use it with a keyboard anyways.
I do primarily use it as a laptop... but ~30% of the time it comes off the case and gets carried for data input. Then it's the best tablet I can spend money on, has a very responsive stylus and weighs about the same as a clipboard and pad.
It's the most flexible computer I own. It could be even more so, which I would appreciate, but that depends largely on apple.
For the work I do I can code *locally* but I *don't have to*. Comparing it to a Switch is completely missing what makes them different. Even an attempted reductio ad absurdum should be a little more rigorous than that.
Do you use Blink by any chance?