When Jesus was alive, there were only estimated to be about 170-400 million people on Earth. Today that number has at least gone up by at least a factor of ten, estimated to be at 7.753 billion in 2020. If these miracles were possible back then, and not now, it could be because the spirit essence is being diluted as the Holy Spirit has to fill and be let in to more people. Either that, or with the rise of communication technology, there is now an enforced silence. Could be a combination of both. Their technology still exists though, flying through the night.

So-called 'Chariots of Fire' I've explained many times - fire is plasma, and so is an electrical arc. UFOs take from an ancient, possibly Universally logical design, and their hulls light up with an electrical plasma arc when in atmosphere, looking like a blue-giant star. The use of the word 'fire' in the Bible could be a euphemism for the modern word we have today, plasma. Think of our expanding lexicon. They didn't have those words back then, but tried to explain things as best as they could without them.