Corporates aren't running Linux not because it's hard to switch. Corporates are sticking to MS because of compliance and admin costs.
It's irrelevant the reason why, the margin any business can take will be constrained by the cost to switch to a cheaper, good enough, competitor.
You are saying it's difficult to switch due to compliance and admin issues. Ok!
LLMs can be swapped easily and open weight models can be hosted to adhere to whatever legal, uptime requirements etc are needed trivially.
The big cloud providers already host and resell open weight models.
The two don't event compare
Basically, companies that are "in the know" and develop software utilize linux as much as they reasonably can. Companies that aren't, don't, but do "use it" kind of transitively through their software.
Where Linux does not hold is in Corporate Desktop IT. Mostly because of inertia of all things. MBAs need their Excel, and let's be honest. These people just... do not learn new tools. They certainly have the ability, but the culture is such that they just don't. So it's not even a choice really. No Windows = No Excel = No serious business person is okay with this.
Maybe, maybe, if your company is mostly developers then you can swing desktop IT linux. But your IT department will fight you, yes they will. And HR will be pissed. And I sure hope your CEO is also a developer. If he's a business guy, well... boss baby needs his Excel. How's he gonna do anything without Excel.