I've used them for years. They're likely the most private VPN, but I still can't recommend them. Their IPs are constantly blocked, and with few servers, switching doesn't help (this was already an issue long before I was a customer). Plus, their macOS app has tons of issues.
Open source software often isn’t preinstalled, may not work flawlessly with many hardware configurations, in general hard to install, often lacks a GUI, has poor UX and UI, and high cognitive load. Also no marketing.
They will be interested when open source devs would prioritize these, but it won't happen
If any devs are reading: please add compact tabs like safari and an extension that summarizes pages/video transcripts and enables LLM chat with that context.