Yes, it’s possible but undesirable for both pigs and fruits to survive without assistance from humans. In both cases, that assistance is offered because humans eat the creatures they assist.
You still haven’t explained why this relationship is good for fruits but bad for pigs.
And how did you determine what the purpose of fruit is? It certainly can’t communicate its preferences or desires.
All you can observe is that the species as a whole thrives when fruit is consumed. But the same is true of farm animals. You are simply projecting the motivations you want to see, like self-sacrifice, onto one but not the other. After all, many fruits are poisonous. That suggests that fruits don’t want to be eaten, but animals evolved mechanisms to safely eat some fruit.
Finally, factory farms certainly cause animals to suffer but from an evolutionary perspective thriving is not about avoiding suffering. It’s about producing offspring, and in that sense farm animals thrive. And given that the OP is about the potential suffering of plants, I don’t see why fruit farms are any less horrific than animal farms.