F1 is a general label. It doesn't tell you anything about the selection process that was used. Did they search through 10 plants? 100? 1000? F1 tells nothing of these details. It is "Mendellian genetics" vocabulary. You can look this up on the wiki for it and it is described properly. IT is simply 2 independent family lies crossed.
F1 will have more vigor than the parents. If they parents were trash, that doesn't mean much, though. It is a comparative benefit, not an absolute quality benefit.
Genetic diversity is generally a good thing.
It's funny, F1 are supposed to be less consistent, but i find they are more consistent. I think a big portion of the deviation of typical plants is more about the inbreeding. An outcropping species do not tolerate excessive inbreeding well. I grew some sweet seed f1 Green Poison (or whateer the fuck stupid name it had like most of these seeds) and all four plants looked the same, smoked the same, tasted the same and yielded like champs. I rarely see that from more severely inbred plants.
Honestly, do 12 year olds come up with these strain names? Bwahah. It feels so unsophisticated.
Anyway, read the wiki on mendellian genetics and avoid the bro-science info.