Your essentially asking why metamorphosis occur in nature, when any given shape and survival method at it’s various stages is sufficient, taking Occam’s Razor, while taking note some life, say a Cicada, has adapted to random hibernation cycles for it’s Broods so Predators can’t easily expand their populations in anticipation to hunt them. Your looking for a mathematical law?
I can give you a portion of it, worked out part in Iraq. I was stationed in Alaska when deployed to Iraq, and noticed Iraq’s cooler temperatures was very similar to Alaska’s warmer weather, yet both had seasons. In Alaska, life explodes around May to September. Under similar conditions, it goes into hibernation and dies in Iraq during it’s winter. Was very stumping to me.

This is from the inverse square law… but the graphic works similar here…
Lets say we know all life is of linear progress, with a shared point (let’s just assume so) some few billion years back, at point S.
We are all cellular life, be it single or multi cellular life, so have a minimum and maximum theoretical size for single and multi cellular formations. A cell too large (like in Star trek that sometimes trapped starships) isn’t going to work on a gravity bound world… it will flatten and explode, organelles never meet up, don’t even get me started on cell division. Same with our multi cellular sizes… eventually your going to get to a size where you become like the giant reolucator blob from Stargate Atlantis, and the forces of nature in mass make it impossible to operate and sustain cells. You can have a ocean full of plankton, but you can’t have a cell the size of the ocean… tidal forces would rip that up. So there is a limitation on size.
If there is a set of limitations, then we can suppose there is a Goldilocks Zone, even more than one, in this graphic called A. A particular life form thrives best here.
R gave birth to the formation of A, everything that was A is in R. Early Homo Sapiens in Africa, flaking Flint and hunting elephants, living in caves is R. Modern Civilization is 3R, and no one uses A that much, we’ve adapted to metamorphosis… we have different technology and social function cultures for different stages of life. A is but a minor subset of options, a ancestral form everyone knows of, hums in the background, we sorta partake in, but not really.
A reformation would be a reset to a single square like R, ideally A, but rarely is. The Protestant Reformation in Europe didn’t return Christianity back to simpler Christian roots, it got rid of Christianity, and forced Northern Europe to embrace a new, simpler Post-Christian religion. It fits the diagram above… the older Catholicism still has A, Protestantism does not (say, Apostolic Succession). However, Catholicism still has that trait that gave birth to Catholicism in it, and so is related in ways other than mere historicality, it shares some of these ‘new’ genetic traits.
I think more or less, the capacity of cellular proteins favor mutations… whatever mutations that doesn’t kill it, in replication. The vast reservoir of mutations that make a species, that make a genus, evolve form to match these Goldilocks Zones of Plenty… a species evolves to adapt to ecology. Its really hard for random mutation to eradicate genes built in to play conservative… Iraq borders The Zargos Mountains, swamps change to deserts a lot there, niches pop up… life gets trapped, expand, trapped, expands. Yes… it can grow in a lush, hot river valley, but all life in Iraq MUST specialize in the distant Zargos ecosystem. You see mutations… some plants sprouting early, but not much.
I suppose if you knew the right ecological triggers, you could convince a plant it was it’s spring. My theory is, you can farm above the Arctic Circle… definitely enough sunlight and temperatures in the summer, but how does a plant know it’s winter? Does it really gave a biological click, or is it responsive?
My idea is, if you dig a warehouse size plot in the thermofrost, board over it in the winter, pile on snow, it will never drop below Freezing. Every few seconds, shoot out a light half a second long, simulating intense sunlight. How much, I dunno… needs tested. I think you can maintain a lot of foods on live plants this way… growth will be retarded… but the plant won’t know the time difference. It will then sluggish, colder, but won’t freeze (minimal use of a occasional heater, will keep the place warm).
I would love nothing better than go to Deer Run, or Barrow Alaska and try it. The goal is to trick the plant into thinking, still at it’s height, it is at it’s Goldilocks Zone, and go through the motions of growth and fruit production, despite it’s actual metabolism going slow from cold conditions. Hypothetically, you could harvest in mid January or February a otherwise impossible crop, at the rate you choose… just don’t send a Epileptic in, the flashing might give them a seizure. When the sun comes back, pop the roof off.