Prisons and Airports are both among the most secure places we have on earth, protected by guards, so that their residents (inmates, passengers) don’t mix with everyone else.
The core difference is that the prison is isolated so that the bad guys stay in, while the airport is isolated so that the bad guys stay out. To get into the airport, you must demonstrate you are safe, while to get into prison, you must be proven to be unsafe.
In the US prison populations and airport passengers have both increased over the decades, though seem to have leveled off in the past few years, such that we are perhaps at both “peak aviation” and “peak prison”.
Perhaps isolation is not the key to safety.