Brentford are not better than them, but keep in mind, this club is one of those clubs that can surprise.
Chelsea seems to have picked form recently considering the outcome of their last 4 matches in the premier league where they won Brighton by 1:0 at Stamford Bridge in match day 6, also won Fulham while at away by 0:2 in match day 7 and further won burnley by 1:4 while at away on matchday 8 and Last week they drew in-form Arsenal that hasn't lost a match in the premier League this season by a score of 2:2 in Stamford bridge.
Chelsea recent performance has really made lots of people change their narrative about Chelsea as Mauricio Pochettino is keen on making a difference in his managerial role at Chelsea. With their current impressive display so far, the odds might actually be on their favor as Brentford's side isn't too consistent in their premier league campaign so far despite winning Burnley last weekend, Brentford is yet to record a win since their last 3 premier league matches at away. Chelsea winning Brentford will also give them an edge in their home winning though Brentford seems to be ahead of Chelsea in their head to head for their last 3 meetings by winning 2 matches and drew one.
Although they are a little better now, the doubts about them are still quite big. It is very natural when a club of their size gets that doubt, because they are actually one of the clubs considered in this English League. We'll see if they will get another positive result in this match or not.
But for me personally, I still avoid putting them on the betting list.