> Looking for a really good reason to make the jump

Not having to pay for Windows Server licences?

Better start-up performance, likely better overall performance, less resource usage.

Assuming these are specific Windows calls, moving to something more cross-platform you could open development to colleagues with Mac or Linux machines (via VS Mac, JetBrains Rider or VS Code) if there are any.

Options to use Kubernetes or deploy to container services that run on Linux

A few reasons.