It’s basically pay to play to get in the good graces of Windows Defender.
I think all-in it was over $1k upfront to get the various certs. The cert company has to do a pretty invasive verification process for both you and your company.
Then — you are required to use a hardware token to sign the releases. This effectively means we have one team member who can publish a release currently.
The cert company can lock your key as well for arbitrary reasons which prevents you from being able to make a release! Scary if the release you’re putting out is a security patch.
I’ll take the macOS ecosystem any day of the week.