https://documentation.libreoffice.org/assets/Uploads/Documentation/en/GS5.1/HTML/GS5114-CustomizingLibreOffice.html

To adapt shortcut keys to your needs, use the Customize dialog, as described below.

1)Select Tools > Customize > Keyboard. The Customize dialog opens. 

2)To have the shortcut key assignment available in all components of LibreOffice select the LibreOffice button. 

3)Next select the required function from the Category and Function lists. 

4)Now select the desired shortcut keys in the Shortcut keys list and click the Modify button at the upper right. 

5)Click OK to accept the change. Now the chosen shortcut keys will execute the function chosen in step 3 above whenever they are pressed. 

I don't disagree agree that that's technically true. But in practice it's simply not going to happen. My 70 year old mother just wants to use outlook to mail her friends and I've setup het phone to save the pictures she takes of her grandkids (my nieces and nephews) on OneDrive so she can share them easily with the rest of the family. Same thing for my brother and my SiL. For 80 euros a year I get a full groupware experience with no extra work. Is it perfect? Of course not. But even with a higher budget there's no feature for feature alternative.

Hell, the chances of getting my work to switch to OSS cloud subscriptions is higher than getting my family to do it.