Google has added a call button to the local pack on desktop search results. So not only is there a call button on the mobile results but now you can click "call" from your desktop results. This started showing up yesterday morning.
Here is a screen shot but it should show for most business's local panels by now?
I think Google had call buttons on some listings in 2017 on desktop, or at least tested it. But now it seems fully live at least for all my queries.
The first person to notify me of this was @vivek_critics on Twitter.
It lets you call via Facetime or other audio solutions on your desktop computer:
I see it in incognito pic.twitter.com/NdqyWqfjDb
— Mike Blumenthal (@mblumenthal) August 3, 2020
Forum discussion at Twitter.