It doesn’t take Facebook level engineering to architect a substitute for VMware in 2023. Mid market IT contractors are replacing ESX for their clients en mass with proxmox. It’s only a question for enterprise until open source gets good enough.
A tech company can justify 30-50% R&D spend, which is where IT/Software falls.
As a non-tech company like ExxonMobil or UnitedHealth this is a much harder ask while being a distraction from other work your IT/SWE team needs to get done.
Time spend managing your custom OSS virtualization stack is time taken away from managing compliance, security posture, networking, data management, etc.
Why re-invent the wheel when it's cheaper to buy?
If you are running vpshere and move to proxmox, you are in for major differences.
Billions of have been wasted trying to get rid of the vTax. It has been rarely successful.
The open source will be eventually "good enough" like Postgres is "good enough" over Oracle, but this doesn't stop Oracle from taking in $50 billion every year.