When you clear your cache on Safari, all the browsing history, cookies, and other temporarily saved data will be washed off your device. Nonetheless, clearing the cache does not do what uninstalling it does as erasing files, and all personal data. One more thing, if you are clearing the cache, it would be fine but don’t clear Data.
Cache only helps your device to browse information that would be browsed frequently. Clearing the cache of Safari just increases the browsing time of iPhone or Mac up to some seconds, but this is not a big deal for it. It would not harm your device in any way.
Rather, It will benefit you by freeing up space on your device and making your system run more smoothly and effectively. So its a very good idea to delete the cache on safari if you are experiencing any kind of issues or delays in the functioning of your browser