>This sounds a bit arrogant.
The parent thread talks about how the business could not go down even with a triple AZ outage for S3, and I don't think it is arrogant to state they should be paying for enterprise support if that level of expectation is set.
>I think they found better and overall cheaper solution.
Cheaper solution does not just include the cost but also the time. For the time we need to look at the time they spent regardless of department to acquire, migrate off of AWS, modifying the code to work for their multi-private cloud, etc. I'd believe it if they're willing to say they did this, have been running for three years, and compiled the numbers in excel. It is common if you ask internally was it worth it to get a yes because people put their careers on it and want to have a "successful" project.
The math doesn't work out in my experiences with clients in the past. The scenarios that work out are, top 30 in the enitre tech industry, significant GPU training, egress bandwidth (CDN, video, assets), or business that are selling basically the infrastructure (think Dropbox, Backblaze, etc.).
I'm sure someone will throw down some post where their cost, $x is less than $y at AWS, but that is such a tiny portion that if the cost is not >50% it isn't even worth looking at the rest of the math. The absolute total cost of ownership is much harder than most clickbait articles are willing to go into. I have not seen any developers talk about how it changes the income statement & balance sheet which can affect total net income and how much the company will lose just to taxes. One argument assumes that it evens out after the full amortization period in the end.
Here are just a handful of factors that get overlooked, supply chain delays, migration time, access to expertise, retaining staff, churn increase due to pager/call rotation, opportunity cost of to capital being in idle/spare inventory and plenty more.