Yep, that is the point. If you take a look at this list of official FIL sponsors, you can only find German companies and firms: https://www.fil-luge.org/en/about-fil/partners-and-sponsors
Exception's a bakery from South Tyrol which only sponsors Natural Track Luge.
If we are honest, nobody with the exception of Germany, Austria and Italy gives a flying fuck about luge. There will be no money from the US or Asia spent for Luge.
In general, I totally agree that it is desirable to have more World Cups outside of Germany. But that simply won't happen, at least not to that extent you wish for. Viessmann and BMW, who kept Luge alive over the past decades, are not interested in having half of the races at night times in Germany. Moreover, Calgary is currently closed indefinetely.
Btw: It is really expensive to keep a track in shape over the years. Best example is the beautiful track in Cesana Pariol which had to be shut down for economic reasons.