I think if we ever phase out animal agriculture we will be relatively safe. You don't have to worry about superbugs if you don't create places for them to develop, which we effectively do by giving billions of dirty animals low doses of antibiotics indefinitely.
Serious bacterial illnesses in countries with good health systems are already pretty rare. The vast majority of them come from unsanitary food practices
Won't there always be somewhere though? Until we have a fully developed planet with no empty land, there's going to be swamps, tar pits, decomposition in nature and a plethora of other strange things on Earth that could give bacteria places to grow. Not to mention space-bacteria!
If all of our countries with health systems designed for our bacteria aren't equipped to handle more advanced bacteria, wouldn't it take just one explorer to bring back a species-threatening disease?
Sure, but that somewhere would be very unlikely to have antibiotics, making the development of further antibiotic resistance unlikely. Non-antibiotic resistant bacteria is very easy to treat and is essentially a solved problem.
The space thing is irrelevant. You can't develop pharmaceuticals meant to kill things you don't know anything about
It's naive to believe AB resistance is only/mostly created in agriculture.
There is no evidence to that. Even the existence of resistant bacteria in agricultural animals doesn't prove there is a danger for Humans.
In Human tuberculosis for example, resistance seems to happen de novo in Humans, normally, after the patients go through multiple ineffective or aborted rounds of treatment.
Serious bacterial illnesses in countries with good health systems are already pretty rare. The vast majority of them come from unsanitary food practices