I probably don't have a lot of readers in high school, but to those I do have, I say:
Why not apply to a whole bunch of longshot colleges? And how do you know your good bet middle-of-the-road colleges really are a good bet? And what if both the admissions committees at your safety schools take a dislike to you? Then where are you? And how do you know the colleges that accept you will give you enough financial aid?
The online Common Application system used by most of the more desirable private colleges allows you to apply to a maximum of 20 colleges with no need to re-enter basic information. The incremental cost in application fees of applying to 20 colleges instead of six would be about $500, which is nothing compared to the tens, if not hundreds, of thousands of dollars you'll shell out to go to college for four years. Maybe half the incremental schools will require a supplemental essay, so that can mean a considerable amount of extra work, and some want custom financial aid apps, but, still …
The main downside would be if colleges colluded and punished students applying to a lot of colleges. I certainly wouldn't put it past the Ivy League, but I've never heard that they do it on acceptances, although they notoriously colluded on financial aid for many years.
As you may know, applying Early Decision to just one college, in return for agreeing to attend that school if accepted typically gives you a better chance of getting in to your favorite school, but if you don't go that route, apply to a lot of colleges.