Mark Webber, Vettel's Red Bull Racing teammate, must also take a large part of the blame.
This is not the first time that one marque has had an edge over the rest of the field, but it does become a problem when only one of those drivers is claiming wins and is consistently beating their teammate.
And that is what has happened this year as Vettel has finished in front of Webber in every race this season.
It has hurt the championship as the man best placed to challenge the world champion has ultimately provided no competition.
Back in the late 1980s, McLaren had the best car by quite some margin, but it was still exciting at the front as you had Ayrton Senna and Alain Prost taking points off each other.
There was also a season at Williams in 1987 when they were the class of the field, but the races between Nelson Piquet and Nigel Mansell made it interesting.
That has not happened this season and I am not sure why.
Webber was more of a match for the German for much of last season and that caused conflict within the team.
This led to the Australian's infamous comment after winning the British Grand Prix last year, "Not bad for a No 2 driver".
But we have seen none of that aggressive attitude from Webber this season.
I do not know if he has a problem with the car or the set-up, but if you look back he has not been the same since he lost last year's drivers' championship in Abu Dhabi.
He did not perform then and he has not performed this year compared to Vettel and that has been a big disappointment for me.
Yes, he has had problems in the race and some bad luck, but he has rarely got close to Vettel in qualifying, and the one time he did start ahead of his teammate was in Barcelona when he was on pole, but subsequently made a poor start and immediately fell to third.
It could be a case that the car and the Pirelli tyres are just better suited to Vettel, and that is something that often happens in the sport when new regulations favour one driver's racing style over another.
You have seen at Mercedes GP for the last two seasons with Nico Rosberg and Michael Schumacher. Rosberg has consistently got the best out of his machinery, while Schumacher, the most successful driver in the sport's history, has toiled and struggled in comparison.
Webber was right to say that his display in Valencia on Sunday was his best of the season to date, but he was still well beaten by Vettel, and also by Ferrari's Fernando Alonso, as he finished third.
He was probably taking the public relations line, but the Webber of last season would not have been so positive about being third, and finishing again behind his teammate.
He is showing none of the fire that he showed last season, which helped him fight Vettel and make the championship so exciting. Until he finds it again I do not see him competing for wins.
The one thing that he has done is highlighted just what a good job Vettel has done.
Webber has shown that the Red Bull can be beaten as Lewis Hamilton, Jenson Button and Fernando Alonso have all finished in front of the Australian this season, and the fact that Vettel has largely been unbeatable just demonstrates the consistently high level the German has achieved this year.
Sunday's race was a procession, but I am still enjoying this season. The racing has largely been good, and Vettel has been pushed in most of the races.
While the title fight is already realistically over, I still expect there to be plenty of good action between now and the end of the season and think there is still plenty to look forward to at the front.
Johnny Herbert is a former F1 driver with three career victories. His column is written with the assistance of staff writer Graham Caygill
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