Levina's new album is out now, which is VERY GOOD, you should give it a try. It's on Spotify, by the way! I love the new single "Stop right there". This sounds like a cool, "real" song, mainstream but good. Radio-material for sure. Still, this wouldn't do well on Eurovision.
Eurovision nowadays is an opalescent festival of dance, fun, political statements, big celebration, heartwarming cries for peace and love. Nobody wants to hear a dull, mediocre pop song. That's why neither Nathan Trent, nor Anja from Denmark nor Manuella from Slovenia got any far.
Stefan Raab is NOT the solution for everything. His songs were as dull and mediocre as the other but with the difference, Raab knows how to PROMOTE songs properly. Yet he wouldn't do well with Max Mutzke in 2017.
Withdrawal is, like Schreiber added correctly, NOT AN OPTION. Eurovision is one of the most watched tv shows the whole year. As he explained in one of the most recent interviews: paying for Eurovision costs Germany much less than producing a whole Saturday night game show or anything similar. So you can can twist and wriggle as much as you like, but Eurovision is still a big fat WIN for Germany resp. its participating television network(s) and German media environment.
Apart from that, it's OUR audience who chooses the songs. Ok, you can say this year the choice wasn't that great but in the previous years we had lots of songs to choose from and we chose Kümmert (who would've been nothing but last place too, I am convinced) or Jamie Lee. Come on, this is our own fault.