I suppose it depends on which "deep end" you are dropping readers into. If it is dropping the reader right into the middle of an action sequence, some readers will be hooked because what they want most in a story is action, action, action, while others will need a reason to care about the outcome of what is happening, so it is a good idea to at least provide that. Sometimes, that is done effectively by showing what things were like before—the home the character is trying to get back to, the beloved family they are trying to rescue or avenge, etc. etc. Sometimes those background details can be revealed more slowly. One of the surest ways to gain the sympathy of readers is to start with a character in some sort of trouble, danger, or pain. People usually identify with characters who are hurting or oppressed . . . so long as they don't come across as whiney or feeling sorry for themselves. A plucky character defying the odds is generally sympathetic, so you don't have to spend much—or any— time at the very beginning explaining what sort of person they are and what their motivations are. (In fact some writers have used this to good effect, by gaining sympathy for a character who, as the story develops, it very gradually becomes evident should not be sympathized with at all: they are the villain, not the hero. By which time, other characters have come in and engaged reader sympathies and so people keep reading to find out what will happen to them.)
If by "deep end" you mean dropping readers into your fascinating, bizarre, crazy world without much explanation, that can work, too, providing the world actually is as fascinating to readers as it is to you. But even then, it's best not to throw too many unfamiliar names, concepts, situations, and so forth at them all at once, as it can be difficult to keep track or to remember it all. A little strangeness can go a long way at the beginning.
One thing that matters, more than you might think, is how deeply engaged the writer is with what they are writing about. A writer who is emotionally engaged with their characters (but not to the point of populating their world with Mary Sues), who is deeply engaged with the action and the world, can often sell readers on what is happening even if the writing is mediocre or even a bit clumsy. This is why sometimes books that are widely recognized as badly written, unoriginal, and [insert other faults here) go on to become wildly popular. Sincerity in what you write and how you write it, actually counts for a lot. So the beginning that you want to write, because it deeply moves and excites you may be the way to go, despite what popular wisdom might say to the contrary. I say "may be" because as always it depends on the execution and who you are trying to write for. (Hint: write for people who like what you like. Don't try to impress people with the kind of story and writing style you don't really care for yourself. Strive to improve, of course, but also write with sincerity and honesty. Of course that requires that we be honest with ourselves first, and that is not always so easy.)