Florian Grehl of Virten.net comments:
Solid-State-Drives are getting more and more common in ESXi Hosts. They are used for caching (vFlash Read Cache, PernixData FVP), Virtual SAN or plain Datastores. A problem that comes with SSDs is their limited lifetime per cell. Depending on their technology, each cell can be overwritten from 1.000 times in consumer TLC SSDs up to 100.000 times in enterprise SLC based SSDs.
Why guess at how much work your SSDs have been doing? Let ESXi do all the hard work for you.