That it is cheaper at scale.<p>Say you pay 1M EUR to Microsoft for their suite, 10k users.<p>You get an asset manager and a IAM (AD), database, web server, OS, user desktop, word, excel,...<p>All of this integrated.<p>On the other hand you have all the pieces separately, maintained or not, and they do not talk to each other.<p>You saved 1M EUR, which will give you a team of 5 or 7 people who are supposed to maintain and integrate these pieces (the part of work MS does, not the administration you need anyway on top).<p>It may work or not, but this is far from a given.<p>If I had to start the IT of a company today I would go for full SaaS for services, Win10 on desktop, and O365.<p>(just in case and to avoid misconceptions: I like my Win10 desktop much more than a Linux one (tried to switch multiple times in 20 years), run all my home services on Linux and develop open source)