Sadly only for US and UK, or am I missing something?

If you are interested maybe look at this post I made comparing search engines

Don’t forget automatically killing orphans

The problem with web apps is that even if the messenger is perfectly secure your web browser/webview provider might not be. Like with windows recall, even if you have the most secure messenger it doesn’t matter if an underlying function scans your info. This doesn’t mean there shouldn’t be the option for a webapp, but it shouldn’t be the default.