Simbrief often uses the same route as the airlines when generating a flight. You can look up the route on flight aware, which also list the route, and find the route suggested on Simbrief. This works great in free flight but probably not much in career
The sim might not be able to say something like “your flight today is American Airlines flight 106 non stop to London Heathrow” in career because of licensing.
You can erase the provided route and paste in/import a SimBrief route for career without issue provided it has the same origin/destination - that does become a problem sometimes as Career likes to use defunct ICAO codes or very small airstrips that are otherwise not in the SimBrief database. Less of an issue when flying airliners, at least.
Surely there isnt licensing issues with liveries in career mode. The liveries are already available in other modes, what makes career mode so special for licensing?
There’s likely a difference (in the mind of the lawyers representing these brands) between “here have our livery” and “here, officially simulate our real-world business with routes we actually fly in an official capacity.” I know it sounds silly, but I’ve been in meetings that span weeks over the correct shade of red to use on a wall because it didn’t meet certain brand standards.