Hulkenberg has been at Renault since 2017, joining the team after a three-year stint at Force India alongside Sergio Perez.
"Nico is the same age as I am," Vettel said. "I think we raced go-karts together. I don't believe that he's out, and I hope he finds a seat. The problem is that our sport is the best sport in the world."
Vettel added that he feels it is extremely difficult for new racers to enter the sport due to how expensive the motorsport ladder has become.
"Our sport has always been expensive, but it has become so expensive that it's become nearly impossible for normal people to start racing, start to do motorsport at a young age," Vettel commented.
"Why? There's a couple of reasons but I don't want to start because I'd never end. In general, we have very strong championships in Germany, great infrastructure, good go-karts tracks and amazing circuits.
"But if you look at the grid, there are mostly people from abroad. There are not many Germans left. So I guess it's got to a point where it's where you need to be introduced to the sport, and that's the core problem."