My wife writes books. She used mostly Google Docs on her phone and after a few hundred pages the phone app couldn't open her file anymore. We had to open it on

My wife writes books. She used mostly Google Docs on her phone and after a few hundred pages the phone app couldn't open her file anymore. We had to open it on a browser, create a new file and copy paste from the previous. I think her edit history was so big the app couldn't handle. She also tried LibreOffice for a while and one of her documents got to a point where she would open it and it would render just a blank page. I had to unzip the file and extract the text from the xml using a custom parser I wrote. Lost all formatting. Whatever you do, have backups. Edit: in both cases everything was just text with very light formatting. No images, no other stuff that could eat all the memory, just mostly plain text.