They need to see much more than they thought they saw in previous times when so many thought the end of the age would end in THEIR day, and it didn’t.
Every age/era of Christians think some things at their time are “as worse as they can possibly be”, yet, it was not so, even more evil times were ahead.
That's not why people think the end times is near and I doubt that is true anyways.
People are well enough aware that things can ALAWAYS get worse before Christ returns.
And what we're experiencing now is a walk in the park compared to the horrors of the Tribulation.