I agree that Microsoft Stream (classic) are an easy plattform for end-users to adopt, as it is integrated into Teams today.
We have started in the last year, to adopt this among our business users, both to use for meeting recordings to reduce the need for staff to always attend every meeting, but also to create lectures for internal staff, videos published to Youtube for anonymous viewing as so on.
But to be honest, the so called "New Stream" end-user experience are not good. Working in a company where ~50% of our business users have a disability, this cumbersome user experience with download and upload to Stream etc.. will most likely mean the end to the use of Microsoft Stream as an app within our company.
I doubt that any UX / Accessibility designer have been involved and tried to look at this from the end-users perspective.