Since I switched my main system from Windows to Ubuntu, I feel that Ubuntu is much more convenient than Windows (except for document processing operations). So I have always used Google's online document processing website. It has basic functions, but it is far from being as mature as Microsoft Office. I have also tried open source libreoffice and Kingsoft's WPS office for linux. But they both have their drawbacks. One is that they are not perfectly compatible with M$ Office, and the other is that the software is bloated with many unnecessary features (I'm talking about WPS).
Then I discovered the amazing existence of office 365 online. It hardly occupies any local resources on the computer, is fully compatible with M$ Office, and has complete functionality (it's almost no different from the desktop version on the computer!!). The files are stored on onedrive, which is very convenient. It's awesome!!!