No, it’s not.
Because the Peter/MJ romance is only part of the plot of Spider-man, in the comics, in the movies, in the cartoons that are recent enough to involve MJ in any way shape or form.
Now, of course, it’s not much of a spoiler anyway, as half the people watching the movie KNOW he gets MJ, and that’s only ‘giving us what we want’ in the sense of ‘getting it overwith so we can get on with the more interesting stories’.
‘Giving the audience what they want’ for Spider-man covers any number of things - from Peter and MJ getting around to their marriage, to the appearance of Venom/Kraven/Punisher/villain of their choice (Mine would be Kraven…I’d love to see what Raimi does with Kraven), to a guest shot by Reed Richards or Charles Xavier, to JJ Jameson finally getting punched in the face, and so on. None of these finally happening are going to end the Spider-man franchise, because Spider-man isn’t about any of those things. The core of Spider-man isn’t ‘will he get the girl’, it’s ‘with great power comes great responsibility’. It’s about Peter’s endless quest to live up to the philosophy that Uncle Ben put in his mind. The only things that would end the Spider-man franchise’s ability to have interesting stories would be Spidie losing his powers (or dying), or the entire world suddenly ceasing to have any evil - neither of which is ‘what the audience wants’, although the second fails mostly because it’s insanely unrealistic, even by superhero standards.
Which leads us to the problem with the OP:
The idea that every series hinges on a single hook, the resolution of which prevents you from ever telling another interesting story with them again.
There ARE series like that, but they tend to have a limited lifespan anyway, although there’s exceptions.
Spider-man is not one of them.