This suggests that the main thing Linux needs, for broader enterprise adoption, is a much improved "log into something that quacks like Active Directory" solution. Not actual Active Directory, obviously that just contributes to the lock-in, but what else is even remotely as polished and well integrated? I suspect this is the true moat actually. Nearly every actual business has "log into our company managed authentication system and have our communication and basic productivity apps just work" woven throughout the core of onboarding.
Microsoft sure has a lot of warts, but even as a Linux enthusiast, I cannot deny that Outlook "Just Works" with a frankly shocking set of basic stuff. Login for the first time, check your email, hey there's your meeting with your manager on your calendar, and now we can add new events just by putting you in this group, etc etc. There's dozens of little integrations baked in here that a tech enthusiast could feasibly replace in isolation, all of which vanish the moment you turn off the Exchange server or whatever it is. It's way more complex under the hood than most people realize, which is why "ditching Microsoft" so often turns into "Adopting Google Apps", as they have a similar turnkey solution to most of the same problems.
Not meaning to be a big ball of negativity, but as I haven't really explored here... in the FOSS space, what is the equivalent? Which tools are the most polished, and what server backends could be hosted on-prem to gain the same basic integrations with login, email, calendar, chat, and video conferencing?