Except for Severus Snape, we don't really have a basis of comparison to determine this.
The Marauders all became Animagi, which is an advanced form of magic. However, we don't know exactly how advanced, and if it's harder to learn than something like the Patronus Charm.
Many wizards who have the skill to become Animagi probably don't, because it's difficult, can go horribly wrong, takes a lot of time, and probably isn't particularly useful to the average wizard. The Marauders all had a reason to become Animagi. In addition, it wasn't an effortless thing for them to do - it took them around three years to do it.
“Instead they did something for me that would make my transformations not only bearable, but the best times of my life. They became Animagi.’
‘My dad, too?’ said Harry, astounded.
‘Yes, indeed,’ said Lupin. ‘It took them the best part of three years to work out how to do it. Your father and Sirius here were the cleverest students in the school, and lucky they were, because the Animagus transformation can go horribly wrong – one reason the Ministry keeps a close watch on those attempting to do it. Peter needed all the help he could get from James and Sirius. Finally, in our fifth year, they managed it. They could each turn into a different animal at will.” - Harry Potter and the Prisoner of Azkaban, Chapter 18 (Moony, Wormtail, Padfoot and Prongs)
Harry, Ron, Hermione, Draco, and the other students during Harry's year at Hogwarts didn't have any real need or desire to become Animagi, but it's unclear whether or not they had the skills to do it if they chose to. In addition, becoming an Animagus isn't compared in depth with any of the things that people in Harry's year do, so we can't really say for sure that the Marauders becoming Animagi makes them better wizards than Harry's year.
The Marauders also invented the Marauders' Map. That was the Marauders' other bit of advanced magic. While nobody in Harry's year came up with any inventions like that, Fred and George and their various products they invented for Weasleys' Wizarding Wheezes are probably comparably clever inventions, and they invented a larger amount of things than the Marauders did. They didn't invent a map like the Marauders' Map, but they wouldn't have needed to despite their love of pranks and sneaking around Hogwarts,since they had the original Marauders' Map.
Severus Snape is the only one whose skills can be relatively easily compared with the students in Harry's year. Potions was a mandatory class at Hogwarts, so every student in Harry's year would have done it regardless of their talent or desire. None of them were as skilled at Potions as him.