He didn't say black holes do not exist, he said that the black hole theory from prior study and the black hole theory in quantum mechanics clash. The old theory may have been inaccurate.
You must be living in the 1990s still. Black holes are bodies of extreme mass compressed into singularity. The only portal a black hole will provide you is a 1 way ticket to the afterlife. What goes in never goes out for a black hole. Well, what goes in may come out ripped apart for quantum mechanics.
And they're not huge at all. They're actually quite small, infact, more often than not, they're smaller than our Sun. They're just EXTREMELY dense. For instance, even though our Sun is too small to become a black hole, we can pretend on what it's size would be. If our Sun collapsed under it's own gravity to form a black hole, our Sun, which is 1.4 million kilometers wide, will be crushed down to an infinite point of mass called singularity. That gravity would then consume all light, creating a boundary around it called the Event Horizon. When we measure the size of a black hole, where the event horizon extends to is the size.
Our sun, with a total width of 1.4 million kilometers, would be compressed down to a size where it's event horizon will only be 3-5 kilometers wide (or 2-3 miles wide). However, it will have the density of our sun or greater in that tiny space.
