This headline BADLY buries the lede! The real scary stuff is the massive future costs of the blatant vendor lock-in that ALL the big tech firms, including Microsoft, are banking on with “free to the government for a year, undisclosed terms for later” contracts.
This is kinda the same for big enterprises too. They start off with really great deals, then every other part is "only a cheap addon, much cheaper than competing product XYZ". Then when you're completely stuck in the M365 swamp, that's when they turn the thumbscrews when the contract renegotiation comes up.
The thing is: Where is the competition though? Considering that most IT departments don't want to spend an extra dime to do consumer-grade software engineering to do any extra integration there is no significant competition to Microsoft 365 and Active Directory.
Google Workspace is the closest but it isn't even in the same playing field when comes into advanced integration. Microsoft killed all of its competition in 90s and early 00s. Nobody stopped them. Nobody applied antitrust law. Now they have at least a decade ahead of everybody else.
Any competition should have to spend quite a bit extra money to just move all the integrated apps (SAP, Salesforce, CAD software, Exchange extensions) to their environment. To repeat my point, most IT departments want to spend a whole 0 on developing / engineering integrated solutions and developing those require some millions per year at least. Microsoft sells these stuff as low as €20 per user depending on the contract.
Amazon tried with its work suite - work mail, work drive and chime but failed miserably.
It’s now a Microsoft 365 user