30 Years Have Passed Since the Prologue - Chapter 1

It looks promising but honestly for a guy who’s supposed to be as experienced and well-versed as he is, why did he assume that there would be an “ending”?  He didn’t get summoned by some princess priest with humongous bazonka melons for tits calling him “oh hero from another world” in order to kill the demon king and promise to send him back. 

Shouldn’t he have known that despite him being isekia’d this world is entirely its own existence from earth? When you and I finish a long term project or something of course the world is gonna continue existing. I mean, it’s not like the universe ceases to exist when you or I die, reality is not about us . He is even aware that he isn’t the protagonist/”hero”, so why does he assume for over 30 years it’s just a game and not it’s own, self sufficient world that will continue regardless of whatever you do, unless of course you blow up the planet or some sh-t . Literally one of the first things all good isekai mangas (in which there isn’t a direct promise or method of getting back) do is have the protagonist recognise that this is it’s own world, that there are real consequences, and that they have to accept that this is their reality now. He doesn’t even look for some McGuffin that is said to be all powerful and use that to go back, he just assumes that at some arbitrary point in time he will be sent back and sits on his asss complaining that the universe isn’t about him  

I would love it if it ends when mc dies from old age and only then realises that he just lived a full life in reality and not a game  . Though I do doubt the author will let that be it, this probably was actually just a prologue which he’s just completed and the mc is right that it’s just a game. If so, then no harm no foul I guess, though it would definitely lower my rating story-wise.
(Don’t take my big brain critic long af rant seriously either )