You’ve not achieved much here because simply grouping a set of APIs and transaction scripts into a project is not what Clean/Onion/Hexagonal architecture is trying to teach you.

The point of the “vertical slice” is to decouple this sub-domain of the system (whatever it is) from others at all layers including the physical layer (e.g your database).

You haven’t demonstrated that at any useful level. Your example is far too simple and incomplete. It is actually very wrong to have your application coupled directly to infrastructure components, and you have coupled yourself to every underlying framework there is, so that all you see in the code is other peoples infrastructure (eg MediatR, ASP.net, sqlserver, EF, etc, etc)

It is seriously overpromising, and underdelivering, and worse, teaching the wrong approach to others (who you are hoping to admire your expertise).