Pretty sure the 2nd advisor isn’t actually a computer scientist/developer or if they are they are absolutely employed as Technical Sales for a consulting company. Otherwise their answer would have looked incredibly similar.

And they do not markup domain prices. You pay what they pay.

None. The beauty of a federated system is that I can stay in my home and still interact with all of those groups should I choose. If using the local function is important to you, then whichever community you are interested in.

AI Tools - plural. ChatGPT (and OpenAI as a whole) predominantly runs on Azure infrastructure. Microsoft also owns GitHub with its associated copilot. And now all the Microsoft product specific copilots.

Not trying to defend their usage, but there are several forests here that are quite visible.