Re: If your virtualizing --- never get locked in --- if you do it is your own fault.
Sure, you are hardware agnostic, but have you not installed VMware tools or Hyper-V Integration tool? (BTW: Removing VMware tools is a right PITA after a migration.)
Then you need to consider that the backend networking could be completely different between the two virtualization platforms. (VXLAN - I'm looking at you!)
Then you need to consider that the virtualized disk format for each product is also different. Now you're looking at something like Double-Take.
Then you need to consider how different your backups may be done depending on the environment you came from and are going to. (Speaking to Veeam, specifically.)
So - yes, it's possible to migrate from one virtualization platform to another, but it's not as simple as copying a config file and some disk files over.