Desktop, phone, and tablet apps don't really work the same anyway. Except when they're just scaled up. But everyone agrees that's bad.
I see few people use the same apps on more than 1 desktop and 1 mobile OS. They use Windows and couldn't care less what the macOS app looks like. Or vice versa.
It's about branding usually in my experience. Not what users want.
It's not always the same user but a team or entire organization using the same tools, and it helps to unify the experience.
Contrast that with something like Outlook which has a dozen different UIs depending on app or device or website. It causes way more friction than just having the same workflow everywhere.
