That factors into financial incentives, doesn't it?

There are also products that still have licensing costs even when you self host.

I've worked at a large company that self-hosted Atlassian products that were a big part of a full-time team's job.

I've worked at a large company that built virtually all their internal tooling in house.

I've worked at a large company that used cloud-based vendors.

They all had tradeoffs.

One of those companies even forced a migration from cloud based CI to internal CI for cost reasons then stopped us halfway through because they couldn't scale up our hosted CI to keep up fast enough.

I could argue your answer is just as short-term thinking when your critical tools end up costing you more hardware, data center, and salary opex than you planned for (which I have seen).