Encountering bears is one of the things that keeps me from heading into the US wilds. I have an irrational fear of it - much like many people do with regards to sharks. That looks more like inquisitiveness to me, & the way that it's put off each time he shouts clearly shows that it's nervous of people. I imagine curiosity could lead to dinner quite easily! But maybe it just really wants the guy's stick?
No reported bear or wolf attacks in Greece, at least in the recent past so it's not really a direct comparison to the US in either quantities or incidents.
I can honestly say it has never stopped me though, i still believe it's riskier driving to the start of the hike than it is hiking, bears/wolves included.
I can understand why someone would be nervous though, as if a bear is determined it wants to take a taste of you there is absolutely nothing you can do about it.
It can run faster, is stronger, can swim better and for some bears at least climb better, with a shark if you have enough notice you can get out of the water, with a dog you could climb a tree and render it useless.
The guy in the MTB vid got the shock of his life, but it was quick and done with, the guy being stalked is wayyyyyyyyyyyyyy worse IMO.
What a mind screw that must have psychologically speaking, the guy has that stick but it's more for piece of mind than anything else, can't see it stopping that bear, so he has to keep walking knowing he is absolutely defenceless against the bear IF it wants him.
Bears though are a quick reminder that in some areas we are not the highest creature on the food chain.
Odd thing with animals though, their threat perception is very weird.
We go to a dog park and the is a absolutely huggeee Dogo Argentino, owners recons it's 50kg which is about the same weight as my Mrs

The dog came up to my 5kg Jack Russell and they started playing, because the Dogo Argentino's paws weigh nearly as much as my dog it tended to play a bit to rough for Bella, so she snarled and nipped it on it's back legs.
This dog that was 10x the size of Bella shot across the park yelping like it's tail was on fire, every time they've met since it greats Bella by rolling on it's back.
For wild animals i recon that threat perception is even stronger, as if they get even a slight injury there is a good chance it'll kill it over time as it won't be able to hunt effectively.
So if the bear, wolf, yote etc isn't hungry or feels it's young ones aren't threatened, or it isn't backed into a corner, i recon a bit of a show of force would scare most off.
For me it comes down to weighing the advantages and disadvantages.
The chances of getting attacked by a bear in most areas is extremely slim, the chances of having a fantastic time while out hiking/camping though is extremely high.