Also, mobile Firefox has supported PWAs for a long time. I wouldn't say PWAs on desktop would be useless, but they make much more sense on mobile than on desktop.
Only use I've found for them on desktop personally is the web interfaces for local hardware. I did use it when I was playing with stable diffusion for a bit but never fine tuned it because stable diffusion kept crashing.
PWAs are useful on desktop if there's web apps you use a lot every day. For example, some people at my Workplace are in Google Docs a lot, so a Google Docs PWA would be useful. Separate taskbar/launcher icon, separate window in Alt-Tab, and at least in Chrome, Google Docs has some basic support working while offline.
Not really, they dropped them wuth the massive layoffs during which they dropped various projects (or more like the entire teams behind them) and increased executive pay... :/
On Android at least, Firefox PWA's don't seem to support registering system-level things (like 'Share To' handlers) - you need to use a Chrome PWA for that....
The native client has application level access to the rest of your machine. They use this to run process loggers "for the activity display", or the button that allows you to quickly stream a game if it's running. They could theoretically use this access for keylogging or accessing the mic without explicit user permission. Running the Discord web client keeps the source of collected telemetry within the webbrowser, which doesn't offer keylogging or process logger features, and requires explicit user permission to give websites access to a microphone, camera, or the screen for streaming.
In Linux the native client is quite bad,especially streaming, as its not hardware accelerated and doesn't stream sound. The browser version doesn't have any of those issues.