The last time I was on a Navy ship was 20 years ago. They carried antimissile defense systems then, I’m wondering how effective antiship missiles are now.
We won't know for sure until they've seen actual use against hostile fire. Both missiles and land-based railguns (using stolen technology from us, you just know the Chinese and Russians have complete plans by now)
With regards to the railgun, if they've solved the issue of firing it wearing out the rails quickly, to the point where we can fire at least 100 rounds before the rails need replacement, this thing would be a game changer. A Mach 5+ projectile is harder to shoot down than a missile -- it will present challenges to enemy defensive systems comparable to hitting a ballistic missile warhead (and on the downside, will give a greater incentive for countries to develop systems which would then have the ability to defend against either railgun projectiles or warheads)