As you say though, another way to go about this would be to scrape the public SV site, which I have not attempted to do. @xnx linked this project in another comment, which seems to do just that: https://tllabs.io/google-street-view-hyperlapse-youtube-vide...
Going back to your first comment, I originally made this as part of an app with an interactive streetview component. I reused the initialization code I had as the base for this. Re-using that code also makes sure the screenshots taken would be close as what you'd see using the embedded streetview (In our project we had a bunch of remote locations without a lot of SV images, so depending on the search radius used when querying for a panorama, we could end up in vastly different places).
However, I realize that I never even considered scraping the public site, which would allow for hiding your identity by not needing an API key. I'll think about this.