If you want to get rich, invent a way to kill ivy that does not also kill people.
Fun fact about goats: you know that 'goaty' taste of goat cheese and goat milk? That's from coagulated proteins - if the producer is gentle with handling the milk, avoiding agitation, and you consume it right away, you can make cheese and milk without that noticeable taste. This is really meaningful for small scale goatery because you can avoid the use of big heavy expensive dairy cows.
Industrial manufacturers are also figuring out ways to stop the coagulation while being able to agitate the fluid. (Convenient if you want to pipe it anywhere)
I've never seen acres of the stuff. It is not a ground spreader type plant, ie it won't run across your lawn or field. It will run along fences and hedges but it does not run into open ground.
https://en.wikipedia.org/wiki/Hedera_helix is classified as a weed in the US and elsewhere quite rightly because it is non-native. It is not a fast spreader at all.
You can peel it off walls and pull roots relatively easily. You can simply cut it in several places and it will die off. You can also paint or spray the leaves with something nasty from Monsanto if killing everything is your bag but it isn't mine.
Source: I used to work for a yard company, and I have it in my own yard.
Shallow roots means easy removal. Ivy isn't actually that pernicious either it seems. I own a company and on our land there are three whopping oaks and there is quite a lot of ivy:
https://www.google.co.uk/maps/@50.9470006,-2.6381093,3a,75y,...
The above link shows a bewildering amount of tree and undergrowth but there are three really large oaks in there and I will preserve all of that lot. It's in a town and a loosely coupled island for a lot of wildlife - it's quite a bit larger than it looks. The oaks are around 200 to 250 years old judging by girth. There's also the remains of some Alms houses to the left of the view, roughly to the right of the pedestrian.
If you look closely there is a lot of ivy there! Also two of the oaks have a lot of ivy cover and I was worried that it might weaken them. But:
https://en.wikipedia.org/wiki/Hedera_helix
links to:
https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/pl...
and we get the assertion: "but it doesn’t harm the tree at all". I'm not totally convinced but I do have access to experts on this (SSDC int al.) so I'll take their advice.