When the logic and interactivity of your page grows, you reach a point where it is really hard to maintain it all with just jQuery. You'll be firing events, and listening for them, and tracking a lot of state that could become global if you don't fight against that really hard.
If the state does become global, then you will have all the struggles that come with that ... something will change "foo" in the global state, and that will cause problems in some completely unrelated part of the page, which will take you hours/days to track down. This is just one example of the kind of problem you can experience.
What the Single Page App frameworks offer is a nicer way to organize all this complexity. You have models, which can fire events. You have Controllers, which (though defined differently in each framework) help you capture and express event listeners in one well-managed location. And you have views to generate changes to the HTML, which usually have enough integration with the models that it greatly reduces the amount of event handling/template re-generation code you have to write.
They really do make a difference, and the MVC frameworks that are out there these days are excellent. I guess the only real way to get a handle on what they do for you is to try a quick demo.
If the state does become global, then you will have all the struggles that come with that ... something will change "foo" in the global state, and that will cause problems in some completely unrelated part of the page, which will take you hours/days to track down. This is just one example of the kind of problem you can experience.
What the Single Page App frameworks offer is a nicer way to organize all this complexity. You have models, which can fire events. You have Controllers, which (though defined differently in each framework) help you capture and express event listeners in one well-managed location. And you have views to generate changes to the HTML, which usually have enough integration with the models that it greatly reduces the amount of event handling/template re-generation code you have to write.
They really do make a difference, and the MVC frameworks that are out there these days are excellent. I guess the only real way to get a handle on what they do for you is to try a quick demo.