Professional mechanics use high grade tools that can cost thousands of dollars each. We have laser alignment rigs, plasma cutters, computer controlled balancing and timing hardware, and high performance benchmarking hardware that can cost as much as the car you're working on. We have a "Kubernetes" like setup because we service hundreds of cars a month.
The shade-tree mechanic wrenching on her fox body mustang on the other hand? her hand-me-down tool box and a good set of sockets will get her by with about 90% of what she wants to do on that car. she doesnt need to perform a manifold remap, so she doesnt need a gas fluid analyzer any better than her own two ears.
I should also clarify that these two models are NOT mutually exclusive. If i take home an old Chevy from work, I can absolutely work on it with my own set of tools. And if the shade-tree wants to turn her mustang into a professional race car, she can send it to a professional "kubernetes" type shop that will scale that car up proper.