I think it might be English ivy? Yea, I guess we could use it somehow... would we just dig some out and plant in patches here and there?

You don't say where you are which would be most helpful. Your picture says eastern deciduous forest zone 7 or lower, guessing. I'll go with the lots of hardy geraniums for a groundcover. No you can't throw out seed. Yes someone will have to dig holes and plant them. It would be wise to mulch the area while the geraniums fill in and to stop erosion in the meantime.

https://www.gardenia.net/guide/great-evergreen-or-semi-evergreen-hardy-geraniums

Thanks!

Portland, OR.

so relatively mild temperatures overall...but rainy from Oct-Jun. always shady.

I'd go with Geranium macrorrhizum if it's mostly shady, G. 'Biokovo' or 'Karmina' if there's more sun.

If you’re in the PNW you want to eliminate all of the ivy ASAP. It’s a scourge there. I have a steep slope with geranium macrorhizum as a successful groundcover but it mystifies next how it can be holding the soul when it basically floats on top of it. Maybe someone can compare the geraniums in this regard. I likewise wonder about creeping junipers, since they are only rooted in the center of an eight food spread.

Too shady for junipers.

In the PNW and a steeper wooded setting, I'd go with a native groundcover. Something like salal (Gaultheria shallon) or creeping mahonia (Mahonia nervosa or repens). Both spread stoloniferously but are not overly aggressive. And they are fully evergreen, ideal for a dry shade situation, pretty much ignored by deer and are recommended for erosion control.

Rarely (never?) available by seed so you will have to dig and plant. But because of their spreading nature you won't have to plant many.

If the English ivy already exists, I'd suggest you leave it where it is but keep it restrained. Yes, it is an invasive nightmare here and new plantings prohibited and existing ones highly encouraged to be removed. But removal in that situation will further destabilize the slope and complete removal in our area is pretty much just wishful thinking anyway. But you will need to stay on top of its maintenance and do not let it spread, flower or set seed or begin to grow up any trees.

You can add a different a different groundcover and let them coexist, but as long as English ivy is in the neighboring yards, it will be forever trying to enter yours. It would be a whole lot easier to use it and just maintain its front edge. It will run over smaller perennials so you'd need to trim it there, too. Still, it's an easy, durable and dependable groundcover.

If you cut it at the base of trees once per year, which takes 2 minutes, its leaves will fall off in a couple of weeks and the stems will follow a few weeks later. Do once per year and it will be a very small chore.

BTW, it's very easy to dig up some root pieces, or start cuttings, and put the ivy where you need it.

I have a hilly lot in Seattle and have had much success with native wild ginger as a ground cover. In the shady spots in my yard, it has established and spread more quickly than the salal and mahonias I've planted.

Please do not spread the ivy with cuttings! It is a noxious weed in the PNW.

Asarum caudaum, western ginger is a great groundcover but I have not found it to be very vigorous in the dry shade common under our native conifers. It typically wants moister conditions.

And no one on the east coast has any business encouraging the planting of English ivy anywhere along the west coast!! It is easily our most aggressive and abominated invasive species

Do people not understand that IT IS ALREADY THERE??? Maintain it well or begrudge it. Your choice. Since it is already there and the neighbors have it, there would be no meaningful, material difference to anyone outside of your yard.

We use logic and practicality on the east coast.

Then we must focus more on environmental responsibility on the west coast! Because IT IS ALREADY THERE is not any valid reason to encourage it to grow or expand any further than it already has. If the slope were any less steep and easier to access and with less of a concern regarding stabilization, then the OP would be highly encouraged to remove the existing population. The OP also stated that low maintenance was an issue and ivy in our climate requires ongoing maintenance to prevent it from arborealizing and becoming more of a menace than it already is. And that takes a lot more than 2 minute once a year, as anyone living in the PNW dealing with an ivy infestation can attest!!

It's ABSURD and unrealistic to think a person can't use what's already in their own yard. Or that they have the obligation to "save the world" when ivy is growing all around them in their neighbors' yards! Realistically, English ivy is NEVER leaving Portland. It's employed covering massive slopes and shaded areas of high end properties, and is everywhere else, too

I know well the Portland area and its climate. It is literally 2 minutes per year per typical tree to keep ivy from climbing. To say it is more than that only demonstrates one's ineptness for managing it with efficient techniques. Nevertheless, thousands of people -- in Portland -- do manage it without all the complaining and hand wringing.

As with any other planting a new ground cover planting on that site will have to have the planting area completely cleared of weeds beforehand - this is critical with low carpeting ground cover plantings in particular - and all the other steps involved with developing a new planting will be required. Including digging the planting holes, mulching and watering during the establishment phase - decorative and landscape gardening is plant husbandry the same as with farming of crops.

Otherwise as you have identified with your opening statement the core issue is that

we have a hillside in our backyard which is all dirt

which means that mulching is called for whether any additional plants are incorporated into the existing assemblage or not.