Personal space demands of robust plants tend to invade the lives of lesser neighbours. They receive shade, whether they need it or not. They may even fade as the sun disappears, when their brave long shoots sent beyond their normal size, can't reach. Longer roots or bigger root systems tend to win races to nutrients and moisture. Rough branches will whip defenceless neighbours in the wind.
The king of the jungle gets the lion's share. This universal rule, holds for every animal and plant. Humans apply civilisation varnish to mask the effect.
The will to live is demonstrated in a relentless competition in which all species participate. Losers find short or long term solutions or perish. They don't say: "Before I succumb to your dominance, I'll flower and my seed shall await your death by fire or age for the return of my clan!" They'll do just that to the best of their abilities.
Every ecological niche generates its own opportunities. Plants thrive on cross-species closeness; a plague on monocultures! Their competition is unlike that of athletes in one race with identical rules for all. They all use every opportunity nature and the neighbours provide, each according to a slowly evolved, unique set of specific attributes. (The word specific is not so often used in this original sense anymore!)