@André Polykanine Yes @Delta Chat is an electron or tauri based app. It's verry accessible on both windows and linux. I don't know for sure about the mac. There is a native app for android which is also very well designed in terms of accessibility.
For desktop, There are two flavours. Originally I was more excited about the tauri edition as it needs less resources to run, but recently serverless audio / video calls powered by webRTC are taking shape which is going to be added into the electron edition first.
When using the desktop app it's best to keep NVDA or other screen readers switched into focus mode most of the time and use browse mode as a mean to proof read something if needed.