Much like how we needed to give up determinism when moving from Newtonian mechanics to quantum mechanics, now we need to give up spacetime in order to expand our theories to explain all the mysterious phenomenon we struggle with today. Yes, that means our notions of 3space+1time HAVE TO GO. I would not worry too much about the mysteries of space and time and remain transfixed with questions like "What is time?" because the next layer of truth is way more intricate than that. I am not saying that space and time are wrong in all contexts, our future theories would have to reduce to relativity much like relativity reduces to Newton when you take certain limits. What I am saying is that worrying about the "nature of time" is much like worrying about the waves on a beach when there is a whole ocean to explore.