Because honestly, Office is pretty great for what it does.
I know a lot of folks here can’t get over it being proprietary or all the other anticompetitive stuff Microsoft has done with Office, but once we got M365 at work, a lot of my work life got a lot easier.
Any time I have tried to use LibreOffice or other alternatives, I feel like I’m giving up ten years’ worth of quality of life improvements. That’s generally my experience with 99% of FOSS stuff - fully functional but dogshit to navigate and use.