And I counter point b with Sam Ryder. A decent song and good performance, as far as these things go, and he won the judges vote.
You can tell if a eurovision song is a good one if it actually gets played on the radio acouple of years later.
Only a few songs I can recall that lived on pass their eurovision performace.
Here are a few that lived on-
waterloo, abba
Brotherhood of Man - Save Your Kisses for Me
Cliff Richard - 'Congratulations'
Sam Ryder - 'Space Man'
Katrina and the Waves - 'Love Shine a Light'
Gina G - 'Ooh Aah... Just a Little Bit'
Mans Zelmerlow - 'Heroes'
Rosa Linn - Snap (the song even was big in the usa charts)
My favourite is Barei with the song called "say yah".