I mean you can certainly make the argument that none of it is really his fault, and his life is a net positive in a lot of ways. But that doesn't mean it's out of character for him to make that choice. For one thing, we can't even really be sure how on board Goku would be with his own resurrection outside a situation where the planet was actively in danger like with the Saiyans. He's known since he was a child that death isn't all that bad, and he's just not the kind of person with that sort of material desire to need to live forever. He died by choice, and I think he'd be perfectly willing to "live" with that disregarding all other factors. But then also everything before the Androids and Cell was pretty self contained, then there's all the revenge plot stuff, but also Cell in particular shows up and he's like this really dark reflection of everything that they are, very much a bad end for their pursuit of martial perfection. Cynical to the point of nihilism where he was going to destroy the planet just to express all that power that came from them. Vegeta is awful, but Goku saw value in him and something that could be saved. He plays it so cool leading up to the Cell games and while fighting Cell, and we know that's for Gohan, but I feel like he looked at Cell (and remember, he's taken his ki senses to the point of telepathy where only a couple old masters ever pulled that trick off), and just saw a big all-consuming void. He's not a despot like Frieza; he really wants, in his self perfection, things that are like what Goku aims for but cracked. I don't think it's unintentional that he takes a mainstay event of the old series and turns it into his personal vanity project to show off before he blows up the planet. And we certainly can assume that Goku would be able to sense it every time Cell wiped out another city with powers he got from Goku. And if you really want to trace it back, Goku only ever really fought the Red Ribbon Army out of sentiment for the four star, so it's not like he's sitting on a ton of moral justification for the events that lead into this. Much as his actions are justifiable and have a positive effect, an adult looking back could easily just view it as violence begetting violence for no real purpose.
So that hits pretty hard. And then he realises Gohan doesn't like fighting and oops he fucked up (which I discussed in the good dad/bad dad context earlier), and watches his son pay a traumatic emotional price for that while this smirking monster made out of all his powers gets ready to kill everyone, and I dunno. I feel like that might have made him "ready" to move on and make way.
I think Toriyama is a much better writer than he gets credit for. He's an amazing artist, and especially really good at composing scenes, but he's also kind of a born serial author who is really really good at throwing a ton of details out there with no planning (pretty much all statements we have suggest that he plans like one chapter ahead at most), and bringing them all together in pretty consistently themed stories. But he writes comedy and silly power escalation fight comics, so no one really cares.Thread about something completely different devolves into a Dragonball argument; having flashbacks to the old board. ^_^
A cartoonist I like, last summer read through the entire comic series from Dragon Ball to the end of Z, and tweeted a lot about it. He had some interesting things to say, so I collected all the tweets in a moment. It's a good read that you can see here: https://twitter.com/i/events/1297794720442195970?s=20 (note that I only filed the first tweet in each thread when there were threads, so you have to click through them a bit if you want to see EVERYTHING)