Windows + office + account and identity management all come with Ms 365 business in the first tier past family. For about $15 or $16 a month you can use InTune to set up logins and select enrollment with MFA as well a provision computers and management with InTune including Boyd self enrollment for laptops, Android, and Apple. All your files get rbac, backup, and recovery from day 1. You can, and I would recommend strongly against this, even manage your osx devices from InTune.

It's very slick and there is a reason business use it. This thread is somewhat delusional on how easy it is to manage and how terrible office 365 is.