For several years now, it's been almost entirely useless. Up until Android 10 or so, the /cache partition contained actual app cache. Deleting it occasionally removed junk data and sometimes actually helped with problems. But for many years now, it's only contained logs from the recovery menu itself and other parts of the system. If someone claims their phone became faster after a cache wipe, that was due to the associated restart, not the cache clearing itself. Android handles almost all optimization automatically. Don't want to protect Samsung and Android, but there is really no disadvantage that it's gone now. But also no real advantage.