On one level Harari is right... Humans are an optimized solution to a set of environmental problems and technology has removed most of these environmental problems leaving many people to feel like they're leading depressing meaningless useless lives. When a person is working together with a small team of others to accomplish a difficult goal and becoming exceedingly proficient at the necessary useful skills to accomplish this goal that enables them and their children to survive, the person is "in their element"... picture a native American buffalo hunt or something like that. Most modern people don't fully get to experience the elation of "being in their element".
Technology has created a new type of environment to which we are not biologically or psychologically optimized and this has resulted in mass scale poor physical and mental health.
Sure there are some people who are self-motivated learners and achievers who thrive in this environment where all basic needs are easily met so that they can focus on achieving more lofty and esoteric or artistic goals for themselves... the Lex Fridman's and Elon Musks and Alex Tsakiris's... But for most people, solving all their basic problems destroys them.
I'm not saying the answer is to destroy technology and revert to a more primitive era (this was Ted Kaczynski's answer) although some part of me kind of wants to see that happen. I think most preppers kind of want the collapse to happen. Perhaps as Suspicious0beservers argues, the sun will go micro-nova and give us the real Great Reset.
Elon Musk's answer is: go find a new challenging environment (Mars) and merge with technology (Neuralink) so that we can become optimized for the new type of environment we are creating for ourselves.
Harari's answer is: lots of people probably just need to die and others will probably find meaning in virtual reality worlds or self-medicate with drugs and we need a new religion to help people find meaning in this new environment. I do agree with the last point. We will invent a new religion and it is already in process.. I think the new religion is that of the simulation and with this new technological spin all the old myths and religions could be recovered and reformed. For example: saving your soul is actually a thing... You don't want to delete any copies that were successful at achieving the goal but those that didn't do so well may be discarded. UFO/UAP sighting? Must be the administrators avatars popping in to check on things in the simulation they are running.
Here is the new religion of the simulation being indoctrinated into young kids:
NDE's are the life review of your stats and missions accomplished and achievements unlocked before you respawn and while you glance at those you can see for a few moments the game continuing on without you.
People are already exploring the idea of falling in love with an AI... is this just a fractal repetition of the "Sons of God" falling in love with the "daughters of men"?
Is life a game? Yes. Does that mean it isn't serious? No. Pain and threat of loss are what makes anything serious. The more potential pain and loss there can be the more serious the game. If you voluntarily give up everything: possessions, goals, ambitions, and make peace with the pain, then life is not serious. It will hurt a lot less. But what is the fun in that?
Regarding questions of free will and pre-destiny where NDE's reveal key events far in the future ahead of time...
There is no such thing as completely free will. Meaningful choices can only exist within a structure that limits those choices. Like JP's example... "Let's play a game!"
"Ok."
"Your move!"
"Uh... what do I do? What are the rules?"
You need rules to play a game. You need limitations on actions in order to take actions.
We have free will but only within the bounds of a structure and there is a structure organizing the events in our lives. Just as in many games/simulations, you have a lot of freedom to move around explore, but to keep the story progressing you have to proceed down the path and talk to certain characters and complete certain tasks. It is a mixture of high level planning and free will and that is how I think our lives are structured.