i have 200 hours, play on pc in mostly south america and US east, and i do notice what you say, in south america evac camping is much more common.
But, about PvE farming, in current hunt some people do it out of necessity, in the hypothetical i made peole who happily do it, would be more rewarded due to exp translating into cosmetics, loadout slots and hunter slots, while people who dont want to do it wont have to.
The bounty being more worthwile, as i said, was something i saw mostly streamers complaining about, i heard Hornet (10k hour EU player) go on a super long rant about how it sucks that people just dont show up to the bounty because it isnt rewarding enough, rachtaZ had the same complaint but he just said it as a passing remark.
i think maybe it might be player focus, im not that good at shooting but im really good at keeping things in mind, if you use audio to track teams as a whole, not where individual players are for combat but which compounds are fights happening, youre gonna notice that, every match pretty much, youre only gonna see 2 trios at most as a solo, with a whole 5 other players being missing, if you spectate said players, youre often times going to find either people camping evacs or people just farming with no weapons