Hillary lost for one reason, and one reason alone: Most people in most states didn't want her to be President. Democrats like to point to the meaningless popular vote, but the bottom line is Hillary didn't take enough states to claim the brass ring. We've gone over the reasons why this happened dozens of times, so we won't rehash them here. Just know that the short answer is this: people didn't want her in office.
That seems obvious to anyone who was paying attention in 2015 and 2016, but don't try convincing Hillary. She's got a laundry list of reasons that caused the implosion of her planned ascension.
Here she is, now safely "out of the woods," blaming pretty much everyone and everything for her loss.