The main thing I found was that Mercurial was only easier for the simplest introductory tasks, where Git has largely compensated with tons of documentation, tutorials and, later, improved command-line UI. Once you needed to do anything more complicated (e.g. working on against an upstream repo you don't have commit access to) you tended to quickly end up in documentation lacunae and semi-supported extensions which rotated in and out of favor depending on which year the guide you'd found was written.

My team started using Mercurial a couple years before Git but eventually migrated over because in practice Git was less surprising and nobody had lost data using it.