Where are you buying your paper? For example European paper is made from local wood, (re)planted in a sustainable way; also recyling. If you rely on extra cheap paper made from Brazilian wood that might be an argument. The stronger argument is that paper production is fairly energy and water-intensive.
That said, I would be highly skeptical that an ipad + pencil is more eco-friendly to produce than however much paper you use during its lifetime.
The people using paper probably also have the iPad, so it's probably whether the pencil used is more eco-friendly than the extra disposable plastic pens (which it might be)? Then you'd need to look at product lifetime, which is probably more limited by time-passed for Apple users and products than by actual hours of use??
I think these things are always more complex to analyse than it first appears.
Is the environmental cost to produce and run your electronic device over its lifetime less than the "cost" to use paper over that same amount of time? Honest question; I don't know the answer.
I use a Rocketbook for taking notes, when I fill it up and all the pages are captures digitally (straight to the cloud provider of my choice per page), I just erase it with a do cloth and it's good as new. Pages are a bit like plastic, and you have to use their pens, but it feels like writing in a notebook and serves the purpose for me.
What deforestation? At least in my country there's more forrest planted each year than cut out for all the purposes, including paper production. And given that, the rest of paper production process is pretty environment-friendly compared to producing a laptop.
Study of one, here, but I find typing notes on my touch screen phone causes me to think a bit more about what I’m writing because I can’t go as fast. So I end up having to summarize to take notes. If I manage to flesh out the notes later, it’s not bad. The problem is when I try to take shortcuts by just taking photos or recording audio. You can do either of those things, but it won’t help the message sink in. Only thought and repeated usage/reference will cause it to eventually stick. Active research can help too, if timeboxed. I only learn passively when I can repeat something at least twice, like an audiobook.
Paper is renewable. The rare earth metals in your devices are not. If you want to make this a political statement, you should instead research which paper companies are buying sustainable wood products, and buy from them.
Once produced, viewing a hard copy has zero environmental impact. Every time you open a pdf or or whatever your iPad saves your notes as, (let alone sync it with Dropbox) a coal plant groans a tiny bit and a penguin dies.
That said, I would be highly skeptical that an ipad + pencil is more eco-friendly to produce than however much paper you use during its lifetime.