To the point that, when I've chosen not to use the institutionally adopted LMS, students sometimes ask after the LMS in its absence. Not because the LMS has any particular life-sustaining power, but because they've come to expect it—to be comforted by the inevitability of its use.
OK, but ... an institutionally adopted LMS has the advantage of a known point of access for course information. Students have a lot to manage and keep track of as they make their way through their courses, programs, degrees. If each instructor decides upon a self-selected means of communicating course information etc. significant complexity and mental load is incurred by the student. I see some important advantages to students 'coming to expect [an LMS]' and feeling 'comforted by the inevitability of its use.'