For some layers my projects do pay for MapBox tile service, but for other projects I use OSM extracts and self-made vector tiles. Mapbox charges only for the tile services, and there are multiple data sources out there, with which mapbox-gl works. It honestly the smart thing to do, as without such flexibility, I wouldn't be using their services or libraries at all.
> but a dev I work with has done a fantastic job of integrating street view with map box. I’ll try to dig up some of his code
This would be a pretty popular library, I am sure! The issue is that the Google EULA prohibits the use of their data directly, it has to be accessed using Google Maps SDK. So Google Mutant Leaflet plugin has to use the API to download the tiles and then exposes the Google Layer a custom Leaflet Layer, but it works :) On the mapbox issue tracker, they close all issues inquiring for help in implementing such a custom layer, so if your coworker did this, I'm sure it was a non-trivial exercise, kudos to him! :)
> but a dev I work with has done a fantastic job of integrating street view with map box. I’ll try to dig up some of his code
This would be a pretty popular library, I am sure! The issue is that the Google EULA prohibits the use of their data directly, it has to be accessed using Google Maps SDK. So Google Mutant Leaflet plugin has to use the API to download the tiles and then exposes the Google Layer a custom Leaflet Layer, but it works :) On the mapbox issue tracker, they close all issues inquiring for help in implementing such a custom layer, so if your coworker did this, I'm sure it was a non-trivial exercise, kudos to him! :)