The classic issue here is the lack of evidence could mean it didn't happen or that that the evidence is expertly hidden.

However the American spy network is large, well provisioned, has no compunction about spying on Russians and was controlled by Democrats when the alleged conspiracy took place. If there is no conclusive evidence of collusion then it didn't happen.

The idea that the Russians are better at influencing the American people than the Democrat and Republican campaign machines is jaw dropping. It doesn't make any sense. Trump could have found more capable people to collude with if he wanted to.