Office on the web is actually great. They did the hard work of making it work with most of the features you want to use. It's definitely better than Google Docs. It's a daily driver for me. Yes, sometimes I'll switch over to the corresponding desktop app, especially if I want to copy paste images e.g. select a range of cells in Excel and paste them as a picture in Powerpoint. The switch from web to app is usually seamless. (I'm on a Mac).