If my spike isn't related to the major I want, will that hurt my application and admissions?

I really disagree with OptimalMIT I say as long as your EC isn't Ballet and you want to run a Ranch near anything is fine as long as you can find a common theme which helps make a great essay.

So my spike is debate I compete at the national level in regional tournaments and was going to attend state and National Quals before they were canceled and I want to go into engineering Communication in Humanities Engineering is a STEM field very different.

My essay about wanting to be an engineer might be like

As a debator I constantly research counter-arguments and arguments for a variety of topics. I want to be an engineer because I will constantly have to problem solve and will have to look for solutions. As an engineer I will also have to articulate solutions to clients and debate will help me with that. Blah Blah Bleh Blah Blah.

You get the picture and you said you want to apply to more prestigious I take that as top 100 schools in the USA

At US News the 104th ranked national university (tied) is Tenn USF SC Oregon I don't think anyone will say these are ultra-competitive and Oregon is a member of the Ultra-Prestigious AAU and when I talked to an Oregon admission Rep they were very chill on ECS and just want commitment and when you tie the spike to your major that is a great thing. I recently an essay for John Hopkins about potatoes and how they tied it in was phenomenal.

https://apply.jhu.edu/application-process/essays-that-worked/

Hope this helps!

Yes, the extracurricular activities should be related to the field you're interested in; nonetheless, you said that you live in an unresourceful area, so it really depends on if you demonstrate your passion for tutoring. I hope this helps.