I plan to establish a club on campus my upcoming senior year. Would this be suitable to add to the extra curricular activities on my college apps as it shows leadership? I heard from some that such accomplishments during senior year don’t really matter 
You heard right. Just starting a club and making yourself president is not impressive - it smack of resume padding and opportunism. Why not invest yourself in your existing ECs - use your initiative, creativity, expertise to make something happen that you care about. Not only will you enjoy it more and perhaps learn something useful, but it will give you something interesting to talk about when you apply to college.
I don’t understand how it’s resume padding when it’s something I take great pride in… Bump
I think if it matters to you, then definitely do it. I think if you just make a club and don’t do ANYTHING with it (don’t impact the school/community in any way, don’t write about it in an essay), then it means the club/activity wasn’t really significant to you and that you just created the club to resume-pad.
However, if you’re really passionate about the activity, then write about it in an essay or something, and it definitely won’t be resume padding, at least that’s what I think.
Establishing a club which corresponds to something you’re passionate about is a great achievement. Not sure why anyone would think otherwise. Just ask yourself this: “If college applications were meaningless, would I still derive joy from taking this initiative?”
Here’s a personal anecdote just in case you’re looking for one. I’m planning to cofound an open laboratory club with one of my classmates next year. If I had no prior interest in science then it would be a fair premise to assume that I am doing so simply to appease admissions officers. However, because of my other achievements and activities within various fields of science, I feel as if taking this initiative would complement my application.
In the end you should do whatever you want.