I suggested in another thread that once or twice during the tour there are pursuit days, where the riders get set off at their over-all time. So the leader would go first, followed, at the moment, by Aru 18 seconds later, Bardet 33 seconds after him, and so on. The leader on the road is the leader of the GC, and sprinters wouldn't get the chance to be anywhere near the front of the race if they hadn't kept their over-all time within reach of the front of the race. If nothing else, it would force a change of tactics by the teams in the days leading up to the pursuit day, because they couldn't afford to have big gaps between their riders if they wanted to work together.
The thing is, so many people see the Tours as perfect as they are, and even mentioning the prospect of doing something to break up the Sunday-club-ride-with-sprint routine is seen as an anathema. Watch the snide comments follow........