Hot take: Megumi should feel way more guilty about the Shibuya incident than Yuji does.
Yuji mainly feels guilt over the countless deaths Sukuna caused using his body, but Yuji didn't do anything irresponsible to set that up. MEGUMI DID.
Yuji was just doing his job the best he could, fighting curses and trying to get to Gojo, lost to Choso, and next thing he knew Sukuna had wrecked the city. He had no way of knowing that was even possible, since EVERY time Sukuna had come out prior had been Yuji's choice (Yuji has struggled to take control BACK from Sukuna previously, but had NEVER had Sukuna take control of him forcefully.
Meanwhile Megumi WILLINGLY summoned a creature he KNEW was capable of killing a Six-eyes limitless user, not knowing what it actually does, just to kamikaze a guy who was clearly not much more threat than a regular human with a sword (Haruta was scared to get close even while Megumi could barely stay standing. Megumi would see this and be able to tell that Haruta was super weak.)
For all Megumi knew, Mahoraga would've caused massive destruction even if Sukuna hadn't showed up, because again, MEGUMI DIDN'T KNOW HOW MAHORAGA WORKS. He could've been summoning a nuke for all he knew.
Edit: people seem to be misunderstanding what I mean here. I'm not saying Megumi wouldn't have known Mahoraga would despawn on its own after killing him and Haruta. I'm saying he didn't know HOW Mahoraga would kill him and Haruta. Megumi had zero info on how Mahoraga actually fights. He only knew it's was strong enough to have never been beaten. For all Megumi knew Mahoraga could attack him and Haruta with some giant attack that wipes out half the city in one go.
Edit 2: Bro the irony of people making "JJK fans can't read" jokes and then proving themselves right by failing to understand that nobody in-universe knew anything about Mahoraga is freaking hilarious. It's spelled out for us clear as day that nobody has ever seen Mahoraga and lived before Megumi and Sukuna. Nobody knew what mahoraga looked like, how it fights, or what its ability was before Sukuna faced it; not even Megumi. They only information actually passed down was that it's the tenth shikigami in the ten shadows technique, and that it's so strong that nobody has ever tamed it. It was MEGUMI who came up with the theory that the previous clan head used Mahoraga against the head of the Gojo clan during their match. Nobody actually reported seeing Mahoraga first hand.