Fair point, but I'd qualify that OOO is only observable for racy programs. In languages with shared memory concurrency, but safety, races are either statically disallowed (Rust), or their results are constrained by a (weak) memory model. Java, e.g. only makes rough guarantees that you don't see out-of-thin air values and that you can't violate the type system. Java also is a little stricter around volatile memory access (they are sequentially consistent, iirc). Also worth noting, some reorderings that you see are not due to hardware, but due to compiler optimizations. Compilers have to obey the memory model, too.

Generally, most programmers shouldn't need to be reasoning about OOO or memory order and be using fences. Rather, they should use libraries that are written by experts that use extra-lingual mechanisms (like compare-swap or fences) to guarantee a higher contract.