The numpad is my number one must-have on a keyboard.
I do graphic design and typesetting at work, which requires a lot of number entry.
On the home side of things, I game with the mouse in my left hand, and use the numpad/arrows/nav cluster for the button inputs, so it's equally important there.

My switch to ortho was dictated by my desire to have a properly laid out numpad in the middle of my keyboard, rather than off to the side.
I tried that with a staggered layout, and it worked, but wasn't ideal.
The ortho layout makes it feel much more natural to me, and I can swap back and forth, from alpha entry, to arrows, to nav cluster keys, to numpad entry, seamlessly.

https://imgur.com/a/mTnEaJh

As far as injuries go, I don't know how much a specific layout, keycap height or keyboard size, factor into that.
I've managed 30+ years as a graphic designer/typesetter, and 40+ years as a heavy gamer, with no issues at all so far.
I attribute that to a conscious effort on my part to always keep my wrists straight, rather than any of the above factors.

My theory is that the tendons are designed to go through the carpal tunnels straight, and should have no problems with doing that, unless there are other, underlying medical conditions.
Where I think the problems arise, is when the tendons have to make a turn, while going through the carpal tunnels.

Think of a piece of barbed wire, running straight through a ring of wood.
As long as the barbed wire is pulled straight through it, there's no contact, and no problems.
If you alter that path, the barbed wire will make contact with the wood, and start sawing at it.
This is what your tendons do to the bones in your wrist, if you don't have your wrists straight, while putting stress on them.
That sawing action creates swelling in the tendons, and the swelling causes the tendons to press against the nerves, which causes intense pain.