This is bad advice in 2026 for most people who would read it, since it advises taking a terrible security posture (give the agent access to everything,) in exchange for a relatively small improvement in workflows.
I say small improvement because my experience is that modern Agents are pretty good, so by the time they've handed it back to me to test it, there are usually only one or two remaining issues that I'll discover as we roll it out to Production.