I think it depends on how you want to define "Borg."
If we're talking about the traditional "you will be assimilated" Borg, then by 2401 they might not be totally gone, but I think they've definitely lost a lot of power and territory due to the whole neurolytic pathogen knocking them down several pegs, among other complications that happened along the way, and it's currently anyone's guess if they'll ever rebuild or can rebuild at this point.
If we're talking about Borg in the sense of beings that are still in some form assimilated and cybernetically enhanced like them, then yes, I think they are...but they are probably not part of the same Collective as we once knew them, having broken away for varying reasons due to all of the complications that had befallen the Borg Collective as mentioned above. Plus, Jurati's Borg cooperative is still a thing, so in a way the Borg continue to live on through them, they're just not malicious anymore.
I like to think the Unimatrix Zero group is still out there somewhere too.
In other words, the Borg are probably still out there, but splintered all into differing groups with differing ideals rather than existing all under the one Collective.
