Floragato developed their trademark flower buds as a means of hunting; they would roll them around the ground in search of burrowing pokemon such as Diglett or Tandemaus, who would stick to the flower's open core, and then bring them up to their mouths to feed.
Sometimes, the target would be too strong and rip the bud off the string wholesale. While painful for the individual Floragato, new Sprigatito would in time grow from the flower's seeds. A pokemon burrow makes for excellent, fertile soil for the young Sprigatito; often, the local ground types would view it as a pet. Sprigatito raised in such a manner do not treat members of whatever species raised them as food, even much later in life. Floragato are not particularly powerful pokemon, and unlike Meowscarada, are not yet in position to protect their young, so detached flower buds likely explain much of this species' surprisingly high level of population growth.
It is not actually true that rubbing a Floragato's flower bud will surely lead to your wishes being granted; if anything, that rumor appears to originate with the Floragato themselves. The sole exception, of course, is if you wish for a new pet Sprigatito. Humans, Paldea's dominant species, make for far more reliable hosts to new plants than any underground pokemon, and Floragato have begun to adapt their behavior accordingly. Some human children are raised in families which do not want a Sprigatito of their own, and fashion toys for themselves based around a Floragato's famous weapon; often, a wild Floragato watches these kids from the shadows, and occasionally even joins in their games.