There's actually a whole host of iPad apps that will give you programming environments for Python, JavaScript, and so on. iSH will give you a full x86 Linux box and a-Shell supports compiling and running WASM/WASI binaries in a simulated shell environment. They've been around for some time, too; Apple really does not give these things the fanfare they deserve.

The main wall that I can see needing to be knocked down would actually be technical, not political. Something like OAMA[0] absolutely would not fix the lack of JIT entitlements or virtualization support accessible to third-party developers in iPadOS. I would not be surprised if Swift Playgrounds is either relying on lots of Apple-only entitlements or compromising on performance[1]. If we had proper virtualization, then we wouldn't need iSH; we could load up a real Linux distro and run a LAMP stack or Docker containers on iPads.

[0] Open App Markets Act; similar provisions were in the EU Digital Markets Act at one point

[1] The screenshots I'm seeing suggest that, at a minimum, your code runs in the same sandbox as the editor. Which means Apple hasn't added any sort of private API that would let Swift Playgrounds properly provision your app. Without a JIT entitlement, the editor would also need to include an AArch64 emulator inside itself in order to provide the App Preview feature. These sorts of things won't matter to casual programming use-cases but would kill a lot of the benefits of an on-device development environment.