Is there a reason you want your CapitalOne credit card limit to be increased? Are you not paying it off monthly?
If you aren't utilizing your credit limit, then worrying about what it is, is being paranoid.
A higher limit will positively impact your credit utilization score. And, of course, it will be there in an emergency. It might not be very useful, but it does have those uses. It also isn't that big of a credit line, anyway. So, I would not worry about it crowding something else out.