I don't normally keep up with news from WWDC, neither does Apple normally release technology for web developers. If you use DuckDuckGo then you're probably familiar with MapKit JS, the feature set available covers the needs of most.
If you do NOT already have access to the Apple Developer Program, this post is probably not for you.

When compared to Google Maps or HERE WeGo(HERE Maps), Apple's take on this is quite refreshing.
MapKit JS provides for free:

  • 250,000 map views
  • 25,000 service calls
  • 25,000 Snapshots unique requests

These limits are PER day!

maps.developer.apple.com-compressor

Similar to unlimited OneDrive storage, when you get close to the limit, you can request your limits be increased.

Apple emphasises on the web, the setup is simple.
You craft a JWT like so

Sign the JWT with your private key, pass it to the MapKit JS library which bootstaps everything and retrieves an access token.

Adam Russell has a detailed post on how to get that setup on ASP.NET Core.

If you want to generate snapshot urls or reverse geocode on the backend then you'll find Apple's documentation sparse on the required endpoints and how to use them.
I have a basic C# project on GitHub as an example of performing such tasks with those undocumented endpoints.