I never used OneDrive, but I was a hotmail user back in the day. Sometime in late 2003 early 2004 Microsoft decreased the max inbox size from 6 MB to 2 MB [1]. A few months later gmail came out with a 1 GB inbox. It was clear to me Microsoft was standing on the wrong side of internet history then and it looks that way to me now.

[1] I could not find a citation for this. Sorry, you will just have to trust my memory from a decade ago.