I hate to say this, because I really hope the succeed, but how have they done at things other than marketing & demos? Are functional phones in people's hands? Do they make calls yet?
I can't speak for the Librem 5, but I have the latest PinePhone Community Edition with PostmarketOS. It works out of the box for most things, including calls. The cameras and HDMI output aren't working right now, but fixes are coming soon for these issues (like next week).
Firefox works well with several tabs open. There are UI issues, but this is to be expected since practically no Linux desktop apps are designed for small screens. However, it's perfectly capable of running a responsive web app or two.
The phones exist and kind of work, but they’re not really functional as a phone. They seem to be riddled with issues affecting all but the most basic of functionality. For example web apps are supposed to be a big thing for the Librem 5 but it can barely render web pages from what I’ve seen in recent videos.
This whole post was written because of a functional phone in a non-Purism person's hand. And yes, they have been making calls just fine for almost a year now.
Firefox works well with several tabs open. There are UI issues, but this is to be expected since practically no Linux desktop apps are designed for small screens. However, it's perfectly capable of running a responsive web app or two.