This app was mentioned in 5 comments, with an average of 1.20 upvotes
Does your wireless provider offer their own app for visual voicemail? My family and I use Cricket Wireless and Cricket has their own visual voicemail app I downloaded from the Google Play Store to use. It isn't as clean as the iPhone visual voicemail, but it gets the job done.
Cricket does support VoLTE (HD Voice). I can't guarantee that you'll have it on your Pixel 2, but if it's capable, I don't see why not?
Visual Voicemail is offered, but afaik it's only through the Visual Voicemail app on Android. I believe it's only native on iOS.
WiFi calling is supported, but again, I can't confirm for sure if the Pixel 2 is supported. As of November 2017, it was still unsupported on AT&T for the Pixel 2.
https://play.google.com/store/apps/details?id=com.mizmowireless.vvm
This app works great, even does text transcription (not always super accurate but convenient for sure)
Here is the link, it should work no problem on 6p. https://play.google.com/store/apps/details?id=com.mizmowireless.vvm