Why complain? Getting back to being 17 is better than getting back to a black job.
Maybe probably because he already did it twice?
I mean, originally he was in his 40's when he got Isekai'ed. So, that means he is 23+ years to the past (from post 2020) atleast.
Then he lived 17 years in the Isekai, after the Goddess had turned him into a 17 years old again (aka., he was 34+ before being sent back).
So, maybe he feels trying to repeat his late teenage years again?
Well, if the current world flow/events aren't different from his past flow/events (atleast when it comes to general world, not the mystical aspect), then he actually has a quick ticket to become really rich.
I mean, if he remembers the right stuff, he can invest in stocks which would rise high in the future, or prepare for events that's gonna happen in future beforehand, etc.