Through visualisation, one can create infinite offerings, eg. mandala and countless universes, to the infinite Buddhas. The amount of merits one can accumulate is vast and countless. Vajrayana methods are very profound and can accumulate more merits and much greater wisdom than the other methods. Effortless is one quality of Vajrayana. Buddha says the mind is the most important.
Mind activates all.
Others may teach according to what they know, whether suitable or not. Buddha teaches according to our level and needs, not according to what he knows. That is the special quality of Buddha's teachings. We have to study and seek a Master to help. We have to choose one teaching and apply it to oneself in order to be awakened.