For enterprise customers, this is an entirely fair objection. You could do this, and many places do. The companies I've worked for use NAS a lot more than they use Dropbox, I can tell you that much for sure in 2024.
OneDrive fucking sucks. If they didn't advertise it constantly through Windows I don't think anyone would know it exists. Google Drive gets used sometimes, but only slightly more frequently than Dropbox.
In SOC2 compliant orgs it's really not very common to store your files with BigCorp. At least, it's one of the no-nos they try to impress on you pretty early.
