I have only ever used AWS, what is the go to cloud provider these days? I know GCP and Azure are catching up, but are people just going back to renting some boxes in a data center and just hosting their stuff on there?
Some orgs deploy Kubernetes on clusters of "bare metal" servers, which is very efficient and cost effective if done above some minimum scale that amortises the cost of the SREs needed to operate the beast.
However, the cloud is not just about compute. The ability to have zone- and region- redundant blob storage that scales to petabytes and has "many nines" of availability is very hard to emulate. Similarly, there are many other turnkey technologies in most clouds that have only complex and expensive on-prem versions.
For example, something like Azure Storage Account "Queues" are basically free and very easy to set up and use. The second you start looking at a highly available cluster of servers providing a queue or service bus, the minimum cost is orders of magnitude higher than a small Azure storage account.