Eero devices require this customer support, but that can be merged with their IOT support team for all other in-home objects. I think Amazon made an exception to their “user support is never our priority” choice because they know it’s the only way to get a physical foothold in our homes, with Kindle and Echo, and I think the burden of Eero support was worth it to them for the mesh networking technology that has been harvested for Sidewalk.
Slack customer support cannot be easily integrated with any existing Amazon support team that I’m aware of, and does not offer a world-changing advantage to that degree.