Mass migration like that occurs (from my memory at least) when the newer alternative has much better functionality, performance, and ease of use compared to the status quo service and has a low barrier to entry (sign up is quick and straightforward). Do any of the decentralized Discord alternatives fit these criteria (honest question, not rhetorical)?

I discovered on Macs, you can unlock a “protected” PDF this way. Just open the PDF in Safari, File > Print > Save as PDF. It outputs a PDF that’s identical, except it’s unlocked (it doesn’t get converted to a bunch of raster images).