I don't know if the billon dollar one will have that feature but this one does has solutions for that. If you click on preview, what you have written is saved, and if you accidentally click on the back arrow, then click on the forward arrow and the text is as it is.
Click on preview and all what you have that you want to post would be saved in a draft, yes and that is good. But I have seen it on a forum before that what you want to post will still just be there is anything happened to your device, as you open the browser back, you will see you post there.
Vut I have used a browser on Android for this forum before, if you close the browse and you open it again, you will see what you are typing, it will not clear away. But upgrade on the browser removed this feature.
On edge on the Windows 11 that I am using, if I do not clear the browser or removed what I am posting a s I do not click on preview, edge browser will let me see what I was about to post before I close the browser. So if I mistakenly close the browser, all I need to do is to open it back and see what I want to post without clicking on preview.