[ycomb9]

Actually the "we can just build this ourselves" is a hard thing to do. Most modern companies do not want to spend money on things like this which they can buy off the shelf. Maintaining a thing like your CI servers need people resources and such resources cost way more than what a service provider will charge. I am sure in some situations it will make sense but for the most part it will be ridiculously cheaper. Now other factors will influence - like missing pieces, unique situations, security concerns etc.

[yen223]

A number that stuck with me is that a 2-week sprint for a team of 5 engineers roughly costs the company somewhere around $50,000 - $100,000 in labour costs.

When framed like that, paying $100,000+ per year for a service contract is likely going to be a lot cheaper than hiring the equivalent team to do it in-house.