With a keyboard case, or in some other fashion, you can surely do so, but why would you ever want to do that over a laptop?
You can get laptops with a decent built in keyboard and full access to Windows, OpenBSD, GNU/Linux, or whatever operating system you want with the wealth of tools that you can get there?
Doing it on a machine as severely limited device like an iPad does not seem to me to be worth it.
What is the attraction?
The key combos on an iPad, even with an external keyboard, aren't perfect so SSHing isn't going to scale well.
It's easier just to use a regular computer than try to pretend an iPad can become a terminal. I should know, I've even tried developing over SSH from my iPhone with an Apple Magic Keyboard.
Just don't.
Use a laptop. If you don't like the built-in keyboard, get a USB or BT one.
First, after a wrist issue I actually found the iPad Por keyboard remarkably comfortable in contrast to my laptop and dedicated keyboards. I'm not sure what it was, but something about either the keyboard itself or the way it forced me to hold my hands was the only tolerable way for me to type for a few months (NB: not an RSI issue, ganglion cyst on the lower side of the wrist, since repaired so this is not a present concern for me).
Second, with Blink + mosh I have an effective terminal into nearly any system I could want (I have not tried remoting into Windows machines and have no interest in it, but I'm sure there's a way). Paired with Working Copy and Textastic I have a pretty nice setup. With the shell, I can do anything manually I'd normally do on my MBP or another *nix system and also get access to emacs (my preferred editor). And with a decent CI/CD configuration, Working Copy + Textastic makes for a good experience (depending on what you're making) when I want to work only or primarily on the iPad.
Third, I've generally been shying away from developing on my home machine directly. That is, I wrap my development environments up in a VM more often than not. The idea of using remote systems or a dedicated VM host machine for this is a reasonable extension.
The only real issue for me is when I'm out and about (which is not so common these days). In my present city there are some substantial cell service dead zones right in the middle of the city. So without a proper laptop hosting the development environment or wifi, that area is off-limits for working while out in the city. However, I also find this city's preference for chain restaurants and coffee shops to be incredibly dull and the areas with more interesting spaces have good service (for me) so that's mostly a non-issue (and with COVID a moot point, I'm not going to those places because they aren't reliably open for indoor service and it's below freezing here still).
If I traveled like I used to, that issue could become a blocker, but that's something I'll deal with when the time comes. Until then, working primarily on remote machines with a terminal or automated workflows works well for me.
They enjoy the use of a tablet for consuming media, but would like to take a step further. Apple themselves put the challenge out, with their "What's a computer" ad, and the whole "Pro" marketing with the Magic Keyboard and whatnot. It does work as a pro tool, but not for everyone, especially us more techie people. It's great for artists and creators in general.
With the release of the Apple M1, I'm more inclined to believe things will remain as they are, as Apple essentially doubled down on macOS. I once believed Apple would eventually release an Xcode for the iPad Pro, but not anymore. I'd argue that if you're not going to make strong use of the Apple Pencil or the general use of a tablet, you're better off getting an M1. It has the iPad's battery life AND macOS.
However I have since then found it to be extremely versatile. Granted I do not use it for coding or accessing SSH. I use it for reading ebooks, taking notes and some light browsing. Particularly the note-taking is an extremely pleasant experience with the Apple Pencil.
I had an Android tablet before (granted it was a relatively low-end Samsung one) and it wasn't nearly as useful. I used it just for flying and even that was a hassle.
But, assuming you use a tablet for something, I can definitely see the appeal of having a terminal on it. A lot of my time on ssh is spent occasionally checking on or configuring stuff, with lots of down time in between. So if you're reading on your tablet, it would be nice to quickly check whether your job completed or whatever.
You can also use Shells [1] and simply run those desktop OS on your tablet. I think this is the sweet spot that lets you truly go all tablet.