This is nothing new. But I was reading an article about it and was a good refresh:
https://lwn.net/Articles/748106/
The article is a couple of years old but I think it is still relevant. Most people I know they have their infrastructure in the cloud. In my current job we are still based on bare metal due to the nature of our business but some years ago we were in that point when deciding what to do with our CI/CD environment. I wasnt involved in that decision (only in the deployment/implementation). Our capex was higher but long term (3y), it was cheaper to build in premise than in the cloud. I agree with the article that when you dont know how things are going to grow, scale requirements, etc cloud is the best choice. Once you ran pass the start-up phase, you should reconsider the position.