TBecause it was an impossible, unrealistic goal?
One of the key hallmarks in whether a campaign is successful or not is whether the goals that are set are realistic and possible. To say Barbarossa had impossible, unrealistic goals only reinforces the claim that it was a less successful operation.
he result was obviously more one sided in favor of the Germans, transversed greater distances, included more men, etc.
If we are to compare like-to-like, then we need to compare the Soviet summer campaign in 1944 (which included Bagration) to the German summer campaign in 1941 (which was really just Barbarossa). I have noticed the habit of people using the term "Bagration" interchangeably with "the Soviet summer campaign of 1944", just as sometimes people talk about the Kiev Operation or Operation Typhoon as part of Barbarossa when in reality those occurred
after Barbarossa had ended. In terms of men employed by the attacker, the Soviet campaign of '44 involved nearly 5 million men while the German campaign of '41 involved 3.2 million Germans plus another 600,000 minor Axis allied troops.
In terms of distances transversed, the results are actually quite similar. It is a similar distance from the D'niepr to the Vistula as it is from the Soviet-German '41 border to Smolensk. In terms of damage done, in absolute numbers obviously Barbarossa did more damage but then the Germans in '44 neither had as many men as the Soviets at any point in the war nor did they ever perform quite as poorly as the Soviets in '41 (except maybe for a few points in 1945). In terms of
proportional damage, the results are again actually similar: both German casualty rates in 1944 and Soviet casualty rates in 1941 were generally 50+% of the forces involved.
A further point is to be made about the decisiveness of the damage done: in the case of Barbarossa, the damage done was not decisive. The Soviets replaced their losses, fought the Germans to a standstill, and then drove them back from Moscow. In 1944, the Germans never managed to replace their losses, in either men or equipment, and there is no indication that they could have done so even without their other commitments at the time... German irrecoverable losses in 1944 were ~3-4 times greater then the entire German force committed to the Battle of Normandy and total casualties were more then
six-and-a-half times greater.
TL;DR: yes, Bagration was definitely the more successful operation then Barbarossa. So was the overall Soviet summer campaign of 1944. Bagration by itself was not larger then Barbarossa, but the overall Soviet summer campaign was.