> The kicker is that updating the dependencies probably just introduces new CVEs to be discovered later down the line because most software does not backport fixes.

I don't understand how the second part of that sentence is connected to the first.

I could have written it more clearly. If you’re forced to upgrade dependencies to the latest version to get a patch, the upgrade likely contains new unrelated code that adds more CVEs. When fixes are backported you can get the patch knowing you aren’t introducing any new CVEs.