Windows has Defender built in and most of those companies are presumably already using an SCCM like Software Center. If they upgrade from ancient versions of Software Center (because let's be honest if they are using CrowdStrike they are probably behind the times) to more recent versions of Intune it includes most of the exact same "fleet configuration" and "fleet anti-virus" tools (including ransomware prevention/quarantine) that CrowdStrike ever provided, only this time with stuff the Fortune 100 companies are likely already paying Microsoft for. They are trading one vendor for another, but the new vendor actually owns the Operating System and has a lot more reasons not to break it with bad update deployments.
It's not like Microsoft has spent the last few decades entirely ignoring these large scale infrastructure needs, they've just been competing with these bloatware vendors like CrowdStrike with significant marketing arms and incredible sunk cost inertia. (Given most of these companies already pay for things like Intune, it's a weirdly doubled sunk cost inertia, but still a sunk cost inertia.)
It's not like Microsoft has spent the last few decades entirely ignoring these large scale infrastructure needs, they've just been competing with these bloatware vendors like CrowdStrike with significant marketing arms and incredible sunk cost inertia. (Given most of these companies already pay for things like Intune, it's a weirdly doubled sunk cost inertia, but still a sunk cost inertia.)