Izuku has had quite the journey since his Quirkless days, but it might even be more difficult for someone who had a quirk and then lost it.
Spoilers incoming for My Hero Academia #162, so if you haven't read it yet you've been warned.
Izuku goes to visit the lovable Mirio Togata, who is still recovering from his injuries sustained from his epic battle against Chisaki and members of the Eight Precepts. As a result of that battle, Mirio lost his Quirk, a sacrifice he made to save Eri. When Izuku visits him in the hospital, however, there is a sign of hope that he could regain it.
Izuku is, well, being Izuku and is taking Mirio's losing his quirk as his fault. That's why he's a bit surprised to find Mirio in good spirits, as the hero is coming to terms with what he is at the moment. Still, he hasn't lost hope and tells Izuku that they've already thought up some ideas to return him back to normal.
"He (Eraser) said that if, sometime down the road, Eri is able to gain control over her Quirk, that he would ask her to return me to a state where I still had my Quirk," Mirio says. "And if that is beyond her ability, that they would try various things to turn me back to normal. The point is, I'm just fine! I've got Nighteye's foresight on my side. So just smile already, would'ja!"
It seems maybe the book is not totally closed on getting Mirio back into the hero game, and that can only be a good thing.
Mirio lost his Quirk thanks to Shin after Chisaki gave him some Quirk-destroying bullets. Shin fired them at Eri, but Mirio leaped in front of them, taking them instead. Despite being powerless, Mirio still went toe to toe with Chisaki, a feat anyone would be impressed by.
Mirio previously had the Quirk of Permeation, which allowed him to phase through anything (and anyone). He also had extreme strength, speed, and durability, and hopefully, someday he'll get those back.