I see the approach of Outposts, just don’t know if I agree with it. Part of the point is it lets you have a dedicated, isolated, on-premise platform without the need to train existing engineers/admins on a secondary technology like Nutanix, ProxMox, etc.
So your calculus should include the cost to rent vs dedicated head count (and let me tell you, companies fucking hate headcount).
Now all that being said, I have yet to see a situation where it really is more cost effective, especially due to the things you mentioned.