The vast majority of tech support is "Level 1," which are easily solvable problems that can be handled by a flowchart (or more recently, by an LLM). Things like "I want to return this item," or "I want to cancel service," or "I want to use a different credit card."

These things generally have self-service options, but many many people are uncomfortable with them and would rather have an agent solve it for them.

Consider that a lot of users nowadays only have a cell phone, no PC. It seems like an edge case consideration but it's really not.