Technically not debut, but Sam Raimi’s Spider-Man was well timed.
It was shortly after the run of the 90s TV cartoon. VFX had just reached a point where convincing web slinging could be made. A few years earlier it would’ve looked awful.
I would also say that along with X-Men it started a new era of super hero movies where they could be taken seriously. Compare it to the Batman movies in the 90s, which are goofy in comparison.