They're the same - as in, you get tagged by a few really good ones, it can flat out ruin your day. But they're real different
All food is the same....but, no, all motor vehicles are the same, all women, all men, all dogs....but, we know that's not accurate.
A right cross and a right reverse punch are two different techniques, entirely, and completely different in my opinion. They're thrown differently, their foot work or foot positions are different, the turning of the rear foot [or not] are different, the shoulders are different, both in usual original position, follow through and defensively, they are countered differently, they blend in with other strikes in combinations differently, weight transference on the legs is different.
And they're different even between themselves - we all have a favorite distance to throw punches from, we all have a favorite height we use as a target. When you catch the opponent in closer than he, or you, planned, you will adapt your cross, or your reverse punch, to that particular circumstance - whether you try to or not, or whether you know it or not.
And again, they both really suck when you get caught.