Why only one side would have an agenda?
The other side with an agenda was the Germans! Seriously, people from all over the world have seen the evidence and see it for what it was, a colossal human tragedy. This
includes the Soviets, who really had no love for Jews and absolutely zero interest in a Zionist state in the Middle East.
I am assuming the basis for holocaust skepticism is the state of Israel existing in the lands previously known as a Palestinian territory. I'm guessing the idea is, that by inflating victim counts, that sympathy among western countries would cause them to support the idea of a new Jewish state. However, the Zionist movement was well underway decades before there was a Hitler. With British withdrawal from the region, the Jews living there took advantage of a power vacuum and basically took the area on their own with very little assistance from anyone.
Then after the fighting, western powers found Israel easier to deal with and an anchor point in the Middle East. I suppose there was also a silly idea of spreading democracy and modern thinking in the Middle East. Goofy I know.
Well, anyhow, with or without sympathy and support, the numbers, the evidence, artifacts was and most still is all there for the world to see. The state of Israel no doubt has benefitted from the horrors of the holocaust, but I don't think there is a lot evidence that it was built because of it.