It never ceases to amaze me how complicated a genuine yagya can be. Certainly you can perform one with just fruit and flowers and coconuts and ghee. This is 84 different items, and I have been involved in yagyas that had double that at least!
Imagine the powerful insight of the rishi or rishi’s who could cognize the subtle effects that these substances can have when used in the yagya fire accompanied by the proper mantras. The ancient vedic culture must have been as advanced in an inner sense as our modern technologies are in an outer sense.