I do like that people like to think he only had a dominant car for a short period. He had THE best car EVERY season full stop. Every track is different, sometimes they had a 0.1second advantage, sometimes a 1.5second advantage. The car was superior but on certain tracks it wasn't quite as brilliant, that doesn't mean it was a poor car by any stretch. Averaged out over the year he had the best car in the last 4 years.
That doesn't mean he would win every single race, nor that it couldn't be close. Not every team is perfect, they've had failures, tactical mistakes their other driver smash in to Vettel and Vettel has hit Webber, Vettel hit other people.
What you mean to say in 1 or 2 seasons they've been painfully dominant in the title race. Great car doesn't always equal points return, ask Hamilton for all the team screw ups or Massa/Maldonado/Webber hits that have screwed him out of points time and time again. Close or close-ish title doesn't mean they didn't have the dominant car.
At no stage in the past four years has there been a season in which the Red Bull wasn't the best car. The advantage Red Bull had at a majority of races each year was unmatched by anyone else. The Mclaren was good for a half season here on certain tracks, and the Ferrari a half season there at certain tracks. But over what 16-19 races of the season the Red Bull has easily had the best car at over half the races and exceptionally close to the best car at the remaining races.