That's not been my experience, actually. The first CI service I used was hosted entirely in Europe, and we needed to ssh in to debug something, the keystroke latency was maddening. We eventually unsubscribed and just bought a big EC2 instance in us-east with Jenkins running on it. It cost approximately 100x more, but our productivity was high and frustration low. Well worth.
I personally think it will breed huge organizational problems if things like CI are slow. "I'll get a cup of coffee while this runs" and then you come back and forget what you were going to release. Soon it becomes "let's get another change into this build before we release" and then it's "well, it's been six months since we've released anything, what do we do." You have to start fast and stay fast if you want to keep developers productive. So saving a couple bucks on computers that are half a world away can end up being a huge expense if you're not careful.
As other comments mention, you also have to be careful about transfer costs. In the CI case, getting your source code into the CI server is cheap, but getting the containers out is going to cost you, especially if you don't make an effort to optimize them. For batch data processing jobs, the same applies; getting the result out is cheap, but getting the data in is going to be a lot of transfer. (If you were using Small Data, you could just run the job on your laptop, after all.)
The speed of computers half a world away is not great either. I remember updating some Samsung drivers once, which were served out of a Korean AWS region instead of CloudFront... and the downloads were glacially slow. Their website is the same way. I couldn't believe how a multinational corporation could push bits at me so slowly. When you're reading their documentation all day, or tweaking drivers, you notice it, and you start to think "next time I'm going to buy Intel". (Compare Samsung's SSD website with McMaster-Carr's website. What site do you hope to interact with again in the future?)
Anyway, you get a bill for compute resources, and you don't get a bill for unhappy employees context-switching all day, so I see why people want to craft clever schemes to save pennies on their compute costs. But be careful. Not every cost is charged directly to your credit card.
I personally think it will breed huge organizational problems if things like CI are slow. "I'll get a cup of coffee while this runs" and then you come back and forget what you were going to release. Soon it becomes "let's get another change into this build before we release" and then it's "well, it's been six months since we've released anything, what do we do." You have to start fast and stay fast if you want to keep developers productive. So saving a couple bucks on computers that are half a world away can end up being a huge expense if you're not careful.
As other comments mention, you also have to be careful about transfer costs. In the CI case, getting your source code into the CI server is cheap, but getting the containers out is going to cost you, especially if you don't make an effort to optimize them. For batch data processing jobs, the same applies; getting the result out is cheap, but getting the data in is going to be a lot of transfer. (If you were using Small Data, you could just run the job on your laptop, after all.)
The speed of computers half a world away is not great either. I remember updating some Samsung drivers once, which were served out of a Korean AWS region instead of CloudFront... and the downloads were glacially slow. Their website is the same way. I couldn't believe how a multinational corporation could push bits at me so slowly. When you're reading their documentation all day, or tweaking drivers, you notice it, and you start to think "next time I'm going to buy Intel". (Compare Samsung's SSD website with McMaster-Carr's website. What site do you hope to interact with again in the future?)
Anyway, you get a bill for compute resources, and you don't get a bill for unhappy employees context-switching all day, so I see why people want to craft clever schemes to save pennies on their compute costs. But be careful. Not every cost is charged directly to your credit card.