What happens if the ratio of cache hit is more than cache miss in a system?

If you are referring to a programmers perspective, that is a good thing. You want the cache to be utilized as much as possible, as in minimizing cache miss / hit ratio. Now, if you are referring to building a architecture, then you also have to factor in cache access time. For example, if the cache miss is really small, but the access time is huge because you made your cache so big, then you would observe worse performance.