GP should be diligent to download his spreadsheets periodically.
At the same time my notebook information is a mix of personal things, work things and lots of other notes, scribblings, and free form information(mind maps, doodling, random writing), I need this just because creating a meta-data knowledge graph, list in the brain is just too much work, stressful and its like a offline store for your brain's functions.
Software tools don't work well for this kind of information input and putting it in either GDrive would not be good. Hence the notebook and pen.
Another big thing I've noticed is the personal productivity system is a catalyst that helps you do work, its not your main work itself. There is little incentive in storing what time you went to gym ten years back. Information/Feature pollution is a bug not a feature.
Unfortunately, Org-mode in emacs, like anything in emacs is a full time project in itself, a huge time sink that has little return on time investment. Use a tool to make your life better. Don't spend time wandering in sub goals trying to make the tool, that makes your life better. The former gives results, the latter is just a long play time sink, where you will forever make the tool better, you will never arrive at making your life better.
Everything can break in weird ways. What you said is equivalent to, well, if the US internet infrastructure was attacked and disabled.
Notice at some point you are just making a wiki. And of course now you have the added effort budget of maintaining the wiki on top of your regular work.
I have seen random posts on the internet where people were migrating their notes systems to org mode or markdown. If you ask me that's too much meta work to do, in order to do your main work.
The entire idea behind making a knowledge system, or a todo system is to help you do things. If you are doing whole project to set these things up, I wonder what the actual goal of this system even is.
I migrated to org from Things some 12 years ago and since I started bare-bones (just todo entries, no special config) and grew as my needs arose, I never felt I had to invest lots of time in my setup.
Agree that some people overdo things and the tools become projects on their own though.