Virtual Buttons aren't really switches or "toggles" -- they are push buttons. Technically, Alexa sees them as Doorbell Buttons which trigger Alexa Routines when pushed.
Currently, Amazon does not let you trigger Alexa Routines with switches. If they ever do allow such things, we would be happy to offer Virtual Switches that trigger Alexa Routines based on their on/off state. Personally, I'm hoping they simply add a "Toggle Action" to Routines. This way, for example, you could toggle a light on/off with one Virtual Button. Unfortunately, this is not a feature we can add for them.
randyth's post in Please add the ability for a virtual button to be a switch and not just a toggle was marked as the answer