Should I expand my extracurriculars?

I would take the extracurriculars you already doing to the next level. As far as I know colleges aren’t looking for the longest list of extracurricular activists, but the depth of what you do. Honestly what you’re doing is already impressive as it is.

So first, I would avoid reading the speculation that people post about why they think they were rejected from this school or that school. No one actually knows what went on inside those admissions offices with one particular application, especially applicants who have been rejected (or even ones who've been accepted). People are usually pretty bad at gauging why in particular they didn't make it at a particular place, and anecdotal evidence on that can often be misleading.

But in general, I'd point out that there's a difference between having a ton of extracurriculars vs. being a jack of all trades—what Ivies and similar schools are going to look for is a combination of breadth and depth. They definitely like it when students have a lot of ECs, but if you don't have any leadership experience, significant responsibilities, big achievements or awards, etc., in any of those, that's going to make it look like you were just doing those activities to put them on your resume. On the flipside, having a bunch of ECs (i.e. 10, because that's how many you can fill in on the Common App), is really beneficial if you've gone deeply into a couple of them, because that fits both the breadth and depth these schools are looking for. So what I would focus on right now is not adding more ECs, but gaining some additional depth—leadership, accomplishments, awards, etc.—in the ones that you have.

Otherwise, I think you're in pretty good shape. I'm curious about your dance and visual arts activities—do you have any big achievements in those, or competitions that you entered and won, or anything else like that? For most applicants, the thing (or things) they've been doing for a decade is going to end up being their strongest activity, and having things you've participated in for that long shows a deep level of commitment and focus beyond what a lot of students have. In any case, I think you have enough breadth right now and should aim for depth moving forward, but you definitely don't have too much of anything.

In addition to experience, you want to have accomplishments that are recognizable and measurable. Looking at your current extracurriculars, it seems that you spend the most time on Dance and Visual arts, and you should focus on those activities and achieve notable accomplishments. Also, just because your extracurriculars aren't that strong, you always have the opportunity to shine in your essays by demonstrating your character and interests.