Cannondale is the only team actively contesting the green jersey in this years tdf!
You can't really say that nobody is bothering to contest the jersey because Sagan is too dominant... he clearly isn't. He isn't fast enough to take maximum points on sprint stages and he doesn't appear strong enough to take maximum points on rolling stages either. The reason he is so far ahead at present in the points competition is because from stage 1 Cannondale appears to be the only team targeting it and so Sagan takes max or almost max points virtually uncontested at intermediate sprints. There are multiple other teams though with riders in a similar mold whom are good enough sprinters (but maybe not the fastest) yet can also get over cat 3 climbs and hold their own in breakaways on stages which feature intermediate points.
Clearly it appears that stage wins rate higher than overall points competition honours whereas in years gone by the green jersey has often been hotly contested by several teams/riders and not decided until the final stages.
You can't really say that nobody is bothering to contest the jersey because Sagan is too dominant... he clearly isn't. He isn't fast enough to take maximum points on sprint stages and he doesn't appear strong enough to take maximum points on rolling stages either. The reason he is so far ahead at present in the points competition is because from stage 1 Cannondale appears to be the only team targeting it and so Sagan takes max or almost max points virtually uncontested at intermediate sprints. There are multiple other teams though with riders in a similar mold whom are good enough sprinters (but maybe not the fastest) yet can also get over cat 3 climbs and hold their own in breakaways on stages which feature intermediate points.
Clearly it appears that stage wins rate higher than overall points competition honours whereas in years gone by the green jersey has often been hotly contested by several teams/riders and not decided until the final stages.