This one thousand times over. Lots of companies have multi-cloud on their strategy but when it's time to actually implement it they find that the cost to adopt hyperscaler #2 is just the same or even more as they spent on integrating hyperscaler #1. While Kubernetes makes workloads portable between vendors, organizational processes for "boring" chores like IAM, tenant provisioning and billing/chargeback aren't. Integration of these processes can get really expensive if you need to re-implement basic "enterprise" process like e.g. four-eyes-principle/seperation of duty on role assignments for each of your cloud vendors and technologies. The IAM systems differ ever so slightly across vendors and that brings a ton of complexity.
The larger the company, the more likely it is that the real bottleneck to cloud adoption is on these processes, not the technology. I know it's hard to imagine if you're coming from a startup background where you can just take the company credit card and get an account on AWS, GCP or Azure in a second. But for developers in big co., acquiring a public cloud account may take months and forms over forms of paperwork, getting roles put into the central corporate directory etc. The investment into these (often atrocious) processes for hyperscaler #1 create a big lock-in.
Disclaimer: I'm a founder at Meshcloud, we build a multi-cloud platform that helps organizations consistently implement organizational processes like IAM, SSO, landing zone configurations etc. across cloud vendors and platforms.