It depends on the industry. A lot of retail companies are moving away from Amazon to avoid having competitive data flow through AWS infrastructure. Some companies may have different business units across different cloud providers but push for strategic consolidation on a major cloud provider for new implementations.

The heavier the use of cloud native solutions and managed services, the greater the effort to migrate away from those solutions. Not all workloads run on containers, and even then those applications will need some code refactoring if they depend on cloud infrastructure services (cloud specific storage, queue services, monitoring, etc)