The point was if he would get a small gap, that nobody, not even Roglic would be able to close it. And Jumbo well knew that as well or Roglic wouldn't have been on his wheel all day and all week. As you could see, on just the short time after dropping Soler, they (primarily Evenepoel) opened up a gap of over 50s. If he had been able to go solo even sooner, he would have gone even harder and could well have won by over a minute. I don't understand why he didn't attack at the moment the break was caught at the top of the climb, as he could have used that chaos to perhaps get a somewhat bigger gap, which he needed to get Roglic in trouble.