Before I started using Zen, the first thing I'd do every time I installed Firefox is disable Pocket.

Pocket used to grab the whole article. It was great for long reads that you didn’t have time for until later. You could read the article from any of your devices (computer/phone/tablet). There was even a “report problem” button for articles that were cut off. And you could set it to download the articles to read offline when you were on a plane or something. If it doesn’t do that anymore than I guess it’s been enshittified by the Firefox buyout.

Instapaper does something similar and still seems to work.

Other read later clients take the loaded article working with articles with payalls. I know Flyleaf does this, although it is Apple only, so you'll need to research for other platforms but they're out there.