Big Companies Do Not Buy Microsoft for the Software. They Buy the Rails.
Identity logins, spreadsheets, recorded chats, and security clearances lock customers in, so replacing a small tool is easy but replacing the platform is not.
All-In with Chamath, Jason, Sacks & Friedberg · Google’s AI Brain Drain, SpaceX's Huge Quarter, Airtable’s 90% Collapse, US Data Fuels China AIA widely shared post about business software put it this way: "nobody buys Microsoft because Microsoft writes the best code. They buy Microsoft because Microsoft is the rail that everything else runs on."
David Sacks, a venture investor, read that line aloud to make a larger point about why big customers stay put. The rails, in plain words, are the core systems that other software depends on. Microsoft is not one program but the base that office work runs on top of.
Start with identity. Active Directory is where employee identities live and where access is decided. Then comes daily work. Spreadsheets hold the figures used in board meetings. The chat system keeps a record of regulated conversations. Underneath is the cloud.
That last part is the lock. Microsoft's cloud has FedRAMP High approval along with Defense Department Impact Level 5 status, approvals that allow a cloud to handle sensitive federal and defense data. That means a defense contractor or another regulated customer cannot casually swap it for something cheaper, because it would have to redo security approvals, move records, and retrain staff.
Salesforce works the same way in government and sales. In a post on social media, Salesforce chief Marc Benioff claimed "15 out of 15 cabinet agencies run on Salesforce." Sacks cited the post to argue federal agencies will not tear out Salesforce and replace it with a newly written tool, and that not all business software faces the same pressure.
So the math protects the incumbent. In one example Sacks gave, one such tool cost about a million dollars a year, while ripping it out would cost tens of millions of dollars. For a large enterprise, with compliance and security on the line, that trade rarely makes sense.
Questions people ask
What is Active Directory?
Active Directory is Microsoft's system for managing employee identities at work. When you log in with your company email, it checks who you are, what groups you belong to, and which files, apps, and computers you can use. Because so many other programs rely on it, changing it means rewiring access everywhere.
What are FedRAMP High and Impact Level 5?
They are demanding U.S. government security approvals for handling sensitive data. FedRAMP High covers federal systems where a breach would be severe, and Impact Level 5 is a Defense Department authorization for highly sensitive information. Getting approved takes extensive audits, so approved clouds are rarely replaced.
If AI can write software so quickly, why can't it replace Microsoft or Salesforce?
Some companies have started rebuilding small internal tools this way, such as trackers and dashboards written with AI coding help. Those replacements work when the job is narrow and has few security or sharing requirements. They do not yet replace identity management, security approvals, audit trails, and connections across many systems.