There are several at Railworks America. If TS 2020 make any, I'm unaware.

Promontory Summit comes to mind.

Clearly things like Wycombe Joint come with lots of custom assets but no locos, coaches wagons etc.

Ye its stopid, You buy a game and then you can barley get any routes bc you need to buy a dlc of 30 euro's or more.

why no one links anything..

Columbia Valley & Pacific on Railworks America is pretty good. I'd suggest getting the donationware RW&A route on the site as well (it's $10 but it goes toward supporting Railworks America)...plus it also adds more assets. CVP runs just fine without RW&A installed though.

https://railworksamerica.com/index.php/download-library/route-collection?view=document&id=3268:columbia-valley-pacific-v1&catid=20:route-collection

With some effort it's possible to make a decent all-freeware route using the CVP, assets from GreatNortherner, and the RCAP.

On sites like UKtrainsim there are several routes that are freeware that do not require payed DLC. They do however require you to track down and install many other freeware dependences which can be a bit daunting and time consuming, but they are free.